Saturday, April 24, 2021

Our Circumnavigation Route & the Ring of Fire


S/V Lynx and our double circumnavigation

Circumnavigating the planet is not just about getting in a boat and going around the world!  There are many other things you have to consider when planning a voyage around planet Earth.  You must take into account the prevailing winds, political disturbances, piracy, bad weather, Visa limitations, and, most recently, a pandemic!  We also want to see a lot of places!  Circumnavigating is not the goal, that is actually just a byproduct of where we want to go and the way the winds circulate around the planet to get us there.

So, let’s start with that… the wind.


The Prevailing Winds:

These refer to a latitude on Earth’s surface where the winds predominantly blow from a particular direction.  Because they generally do so, when sailing, if we stick to a particular latitude, we can expect to find winds blowing in one direction, somewhat consistently.

For sailing, the two prevailing winds which are the most helpful in a circumnavigation are the trade winds (yellow and brown below) and the westerlies (blue).

Westerlies (see blue arrows, above):

These are winds that tend to blow from west to east (taking your boat east).  The westerlies are found between 35 and 65 degrees of latitude.  The problem with the westerlies is that they are pretty far up or down on the globe, and therefore, in the colder regions.  The second issue is that these winds often blow fairly strongly, creating some very rough conditions and large waves.  This happens even more in the southern latitudes where there is less land, and the winds can, therefore, pick up more speed and cause larger waves.  The westerlies are particularly powerful in an area called the roaring 40s, which typically blow between the 40 and 50 latitudes.  For the most part, we intend to stay out of the westerlies.  The exception is if we decide to do the Ring of Fire route, which will take us across the Aleutian Islands to Alaska, going east from Russia (more on that below). 


The Trade Winds (see yellow and brown arrows, above):

The trade winds blow from east to west.  These steady winds are found in the tropics, near the equator.  They typically blow from the northeast in the northern hemisphere and southeast when you are down in the southern hemisphere, both angling toward the equator.  The trade winds are predominantly gentle and therefore, cause less wave height.  Unfortunately, in the hot months of summer, water evaporates, and Earth’s spin starts the clouds turning.  They keep adding water and spinning faster, and that leads to cyclones, typhoons, and hurricanes (which are all basically the same thing, just in different parts of the world).  So, for sailors, what this means is that in the winter months, you can sail west in gentle steady  breezes pushing you along from behind.  They take you west, around the world.  However, come summer, you need to get out of those latitudes to avoid the big spinning behemoth storms.

This is the reason why most cruisers sail west around the world.  Most of the time, we will do the same thing.  More on that in a bit.

OK, so now we know one thing, in most cases, we are sailing west and sticking to the trade winds.  Now, let us look at where we want to go and see things on planet Earth.


Where do we want go?

So, we are head west… but to where?  We plan to visit over 100 countries or provinces; however, for simplicity sake let’s break this down to just major regions.  The red pins mark regions we absolutely plan to visit while yellow ones are only possible destinations:

So, what will make us decide which of the yellow pin destinations are added to the route?  Well, that brings us to some other deciding factors.  Two of these are political unrest and piracy.  Either of these may exclude us from visiting an area.  This could mean just giving it a wide birth or, in some cases, it could change our entire route around the planet!  Let’s take a look at both situations.

 Politics and Piracy:

There are times when politics lead to civil unrest or wars and other times when poverty leads people to
piracy.   We do not want to run afoul of civil unrest or piracy, both are dangerous to our crew's health.  That means, we may need to avoid countries experiencing these political situations.  
The pins in the images (left and below) show where piracy was reported in 2020.  Orange are boardings, yellow are attempted attacks, purple are just suspicious vessel reports.
The places of most concern are the choke points on the route west like the Straits of Malacca.  When it comes to the Malacca Straits, we can just take another route, avoiding that area.  (see piracy map above, from lower Indonesia, we could just duck out at Jakarta and head west).

Another piracy hot spot is the central west coast of Africa in the Gulf of Guinea.  Right now, as you may see from the image (right) there is a lot of piracy in the Gulf, so we cannot go up the west coast of Africa to the Med.  Instead, we would have to cross to South America from South Africa. 

I left the worst for last, the Red Sea (see image, right).  This is the gateway to the Mediterranean Sea, through the Suez Canal.  When there is civil unrest (like the current civil war in Yemen) or piracy (from Somalia, on the opposite coast on the Gulf of Aden, we cannot risk passing through there to get to the Red Sea.  That is a real shame, since the Red Sea is one of the most beautiful places to dive in the world, and it would take us right into the Mediterranean Sea, one of our ‘must see’ destinations.

If the Red Sea is a problem, we might have to sail across the Indian ocean to Africa, turn south, then go around South Africa and then cross the Atlantic to Brazil.  That adds more than 8,000 nautical miles of open ocean to the trip!  We hope that things calm down before we have to make that choice.

If we don't want to risk the Red Sea or the rough waters of the Cape of Good Hope, there is a third option.  We can avoid the Indian ocean altogether.  In that case, we would head north from the South Pacific and take the Ring of Fire.  That route would take us clockwise around the Pacific Ocean, going all the way up to the northern roaring 40s where we turn east.  We then use the westerlies to take us across the Aleutian Islands to Alaska, then turn south and head down the west coast of Canada and the USA.

These three possible routes are the main reason for those possible (yellow pin) destinations on our map.  However, since we are planning two circumnavigations of Earth, so have the option of choosing choose two of these three, depending on the circumnavigation year and what is happening in the world at that time.  Which two routes?  Only time will tell as political situations and piracy change over the years to come.

Now that we know the major possible routes, what else affects our voyage?  The answer is bad weather.


Bad Weather Avoidance

This has to do with two factors, safety of our crew and boat insurance restrictions.  Basically, it is a simple concept, we must stay out of the areas of the world during periods when hurricanes, typhoons, and cyclones tend to form.  We want to do this for safety first and because our boat insurance will not cover us if we are there during those times.  That limits how long we can stay in certain places.  Below is a map of the world with the basic time periods where we must avoid major weather phenomenon.

So, what else affects our route?  Well, some places only let you stay for a limited time.  Let’s look at that next.


Visa Limitations

OK, so now that we know possible routes and weather limitations, what about Visa Limitations?  Some
countries only let foreign nationalities stay for specific amounts of time.  For example, French Polynesia only lets people stay for 3 months.  Australia limits you to six months and, worst of all, by far, is the Schengen grouping of countries.  This means mostly the European Union, but there are some add on countries (see list in image right).  

The Schengen rules are terrible for sailors.  They are not designed for people on boats, they were created for tourists mostly traveling by plane, train, car, or bus.  They do not consider that it can take a week or two to travel by water between two locations.  I have written to the European Union about this, and you can imagine how far I got.  About as far as I can throw the Eiffel Tower.

Basically, the Schengen rules are as follows, you cannot spend more that 90 days out of every 180 rolling days in all of the Schengen Countries (combined).  That means, whenever you leave one of them for a non-Schengen country, the border officials look back through your passport at the last 180 days and see if you have spent more than 90 days in the Schengen countries.  If you have, you are fined and you may even be barred from ever returning!  Yikes!

This makes sailing around Europe a royal pain in the arse and even dangerous, at times.  The danger comes from these bastards forcing you to leave at the wrong time.  For example, you might have to cross the Bay of Biscay at the wrong time of year, without time to wait out a storm, or you will be fined and possibly barred from Europe.  It is insane.

The only saving grace is the UK.  They are not part of the Schengen.  If they were, I’d despair at visiting Europe by yacht.  The UK allows you to stay up to six months and none of that time is counted against the Schengen 90 days.  So, what you must do to visit Northern or Central Europe by boat is spend a lot of time in the UK.  You might even need to wait out winter there, rather than cross the Bay of Biscay at the wrong time.

Now, down in the Med (Southern Europe), you have the same issue.  Fortunately, there are still a few (very few) countries where you can get out of the Schengen.  Right now, Croatia, Montenegro, Albania, Boznia, and Turkey are your only havens… and Croatia has recently asked to enter the Schengen, so that refuge will soon go away.

Turkey is the only large cruising area of these so, while in the med, expect to hang out in Turkey for at least three months out of every six.  These ridiculous Schengen shenanigans are the only way to sail in Europe due to the incredibly stupid European union Schengen country rules.  I fart in their general direction!

And now, the pandemic.


The Pandemic

Covid 19 has messed up travel, big time.  Everyone knows that.  What we do not know is how long it will continue to affect it, which countries will be stay closed, or have ridiculously long quarantine requirements (even if they let you come to their shores).  There is no real way to predict what will happen in the next few years.  Right now, I am glad it is still two years before we plan to start our circumnavigation.  Even when we do, we plan to spend the first year on the east coast of the USA.  That gives the world three years from now to get their borders open.  We can only hope.  Our entire route and timing may have to change it things don’t get back to some semblance of normal by that time.

The Route around the world:

So, with all of these factors forcing our route to certain directions of travel, routes, bad weather timing, and limits on how long we can stay, it is a minefield to plan a circumnavigation.  However, we have done just that, anyway.  Below is one of our projected routes (we have several).  It also takes into account all of the Visa limitations and the damned Schengen rules.

These images show our odd path to circumnavigate the planet.  Most of the time we are headed west, but near the beginning, we go east, to Europe, before heading out for our full trip around planet Earth.  We choose to do this for a few reasons, not the least of which we just wanted to see Europe early on.

The Route:

Year 1:

(Red route) We start in the Caribbean and sail up the east coast of the US to do a full refit of the boat.  Then we head north and take the Erie Canal into the Great Lakes.  Once we reach Chicago, we head down the Mississippi River to the Tennessee River, then back to the Mississippi River to the Tombigbee and out to New Orleans.  We cut across to Florida, then stop in Tampa before heading to the Florida Keys and back around to Fort Lauderdale for a minor second refit (now that we know what else we want).  With our shakedown cruise and refits now complete, we are ready for some major ocean crossings!

Year 2: 

(Navy Blue route) From Florida, we head out to the Bahamas waiting for the proper time to cross the
Atlantic.  When it is time, we head for Bermuda and then to the Azores.  We spend a month there, seeing the islands, before heading to the top of Spain.  We go around the Bay of Biscay, seeing the Brittney Coast of France, then cross over to England, then to Ireland and up the Irish Sea to N. Ireland, then Scotland, back to England, then Wales where we end the year in Cardiff.


Year 3: 

(Yellow route) After winter, we return to the boat and head out in Spring, this time going around the west shore of Ireland and up to N. Ireland, then we across and take the Caledonian canal right through the heart of Scotland, passing through the Angle Staircase and then through Lock Ness!  On the other side, we head north to the Shetland Islands and reach the northern most point of the UK.  From there, we cross to Norway and then head north for the Arctic Circle.  Once we reach the Troll Fjord, we will turn around and head south again, following all the way around to Oslo.  Then we head south to the west shore of Sweden and on down to Copenhagen, Denmark.  From there, we take the Kiel canal through Germany to the Wadden Sea and over to the Netherlands.  We cross the English channel to Ipswich and then head for London.  After that, we come back down the River Thames and store the boat for the winter.

Year 4: 

(Sandstone route) From the cliffs of Dover, we cross the English Channel to France and then head up to Brussels, then Amsterdam in the Netherlands. We start up the Rhine River (a slow slog up current) until we reach the Rhine Valley.  Then the going gets really tough as we go up the gorge against 8 to 9 knots of current.  One that is managed, we work out way through the rest of Germany and take the Rhine/Main canal to the Danube, now going with the current.  Then we head into Austria, followed by Hungary, Serbia, and Romania.  We end up in the Black Sea and go through the Bosphorus, in in Istanbul, Turkey and go down that west coast to Greece.  We go through some of the Greek Isles and then through the Corinth Canal.  From there, we head north to Albania and up to Venice, Italy. Then we head south and go to Croatia and Montenegro.  From there, we head west and sail around the boot of Italy, and then head up the Italian west coast to Rome.  We leave Italy from Pisa, and head for Monaco.  Then we go to the French Rivera, stopping at places like Nice, Cannes, and Marseille.  From there, we cross to Barcelona, Spain, then on to the Balearic Islands.  Finally, we leave the med and go to the Canary Islands, then cross around December to the southern Caribbean.

 Year 5: 

(Neon Green path) Once we left the Istanbul, we finally started out journey west around the entire planet.  We pick up that journey in the fifth year from St. Lucia and head north up the Caribbean Islands, stopping in Martinique, Dominica, Guadeloupe, Antigua & Barbuda, St. Kitts & Nevis, Anguilla, the British, Spanish, and US Virgin Islands and then on to San Juan.  from there, we cut across the Caribbean Sea to the San Blas Islands.  Then, we go through the Panama Canal.  Now in the Pacific Ocean, we head down to Ecuador and launch our farthest voyage, to the Marquesas Islands.  From there, we continue on into the Tuamotus Atolls, then on to the Society Islands.

Year 6: 

(Cyan route) In Year 6, we leave the Society Islands and French Polynesia, heading for Samoa.  We stop in American Samoa first, to reprovision, then head on to Samoa.  From there, we sail south to Tonga.  After spending a fair amount of time in Tonga, we head west to Fiji and tour that nation.  Then we head west to Vanuatu and then on to New Caledonia.  After sailing around there, we turn west again and head for Brisbane, Australia.  Once there, we turn south and follow the coast down to Sidney, ending the year there, for the big harbor fireworks show.

Year 7: 

(Tan route) We sail over to Lord Howe Island and then back to the Australian mainland to head north toward the Great Barrier Reef  now that cyclone season is over.  After reaching the top of Australia, we head into Indonesia, going to the Raja Ampat area for some great scuba diving!  From there, we head north into the Philippines.



Year 8:

(Magenta route) Now we head back south again, and back down to Australia, where we want to explore the Kimberly Islands.  From there, we will head north back into Indonesia and then across to Jakarta, through the pass, where we will take the outside route on the west shore of Sumatra.  Then we do a short hop east to Thailand.

Year 9:

(Purple route) Continuing west, we stop at the British Indian Ocean Territories (some atolls).  From there, we sail further west to the Seychelles.  Once there we sail west to the shores of central eastern Africa.  Then we go southeast to Madagascar, then down to South Africa for the difficult weather region around the Cape of Good Hope.  From there, we head across the Atlantic, stopping at St. Helena and Ascension Island before heading further west to Brazil and then to French Guiana.

Year 10: 

(Amethyst route)  Continuing up the eastern South American coast, we enter Suriname.  From there, we head further north to Trinidad and Tobago.  Then, we sail on north to Grenada, St. Vincent and the Grenadines.  When we cross our wake in St. Lucia we will have finished a full circumnavigation of Planet Earth!.  However, we are not done, we sail on to Martinique, Dominica, Guadeloupe, Antigua and Barbuda, St. Kitts and Nevis, and, finally, Saint Martin.  That also ends our Caribbean time since hurricane season is now coming.  So, we head northeast to Bermuda. From there, we sail east using the westerlies to get us to the Azores.  From there, we head northeast to England, sailing east up the English Channel until we cross at Dover.  Then we go through Brussels, the Netherlands, and back along the Wadden Sea to Germany.  We sail through the Kiel canal and then turn north, heading for Stockholm, Sweden.  Once there, we turn around and head back down the Baltic Sea to the West Oder River.  We enter the canals of Germany and go past Berlin, then turn west and follow canals through Germany, turning south and reaching the Rhine River.  We head down river (this time).  We take canals south through the Netherlands, then through Brussels, and finally, in to France where we end up in Paris.  From there, we take the Seine River west to the English Channel and cross from Cherbourg to Weymouth, England.

Year 11: 

(Jade route)  After waiting out the winter in Cardiff, we sail on back around Lizard Point and back up to Weymouth, so we can cross to the Channel Islands of the UK.  From there, we continue south to St-Malo, France and clear into the Schengen Countries again.  We sail west to Brest, and then go around the Brittney coast of France until we turn west and cross the top of Spain.  We turn south and head out of Spain into Portugal.  We continue around, turning east, and head for Gibraltar, the gateway to the Mediterranean Sea.  We follow the southern coast of Spain up to the Beleric Islands and then over to Barcelona, Spain.

Year 12: 

(White route) Now back in the Med, we head east to the to of Corsica, then across to Rome, in Italy.  We turn south and sail to Messina, then cut across to the southern tip of Greece.  We turn north and head for Athens, then west toward the Greek Isles, seeing some we missed the last time we were in the Aegean Sea.  Once we reach Turkey, we head east along the bottom, all the way to Mersin.  From there, we sail south to Cyprus.  Now we reverse course and head west, sailing to the Isle of Crete.  From there, we sail further west to Malta.  Then we head north up to the east shore of Sicily, then turn west again at the top.  Once we heave Sicily, we sail to Morocco and then on to tour all of the Canary Islands before heading across the Atlantic.

Year 13: 

(Blue route) Now it looks like we are headed off to a second circumnavigation, but that's not the case!  We are going around the Ring of Fire instead.  In Year 13, we head out to the ABC's (Aruba, Bonaire, and Curacao).   After spending some time there, we sail on to the Panama Canal.  Once through the locks, we head for the Las Perlas Islands and then sail off to Ecuador.  We do a second major ocean crossing in the Pacific, but his time we are headed for the Pitcairn Islands.  Once there, we head west to the Gambier Islands, then on to the Austral Islands, and then north to the Society Islands for a brief stop before heading east to the Tuamotus Atolls.  After seeing more of these, we head back to the Society Islands.

Year 14: 

(Fuchsia route) This time, we head for the Cook Islands, then on to Niue, and up Tonga, headed bottom to top.  We then turn west and go to Wallis and Fortuna, before turning south and going back to Fiji, where we do a completely different route to all new locations.  Once we are ready to depart, we head north for the Tuvalu Atolls, then on to the Kiribati Atolls.  

Year 15: 

(Orange route) Now it is time for the true Ring of Fire route.  From the Kiribati Atolls, we head north to the Marshall Islands.  From there, we turn west again, toward Micronesia.  Once we pass through that nation, we reach Guam, then turn north again, following a string of volcanic islands (part of the (Ring of Fire).   We sail northwest, to Okinawa, then north to Japan.  When we leave that nation, we sail north to the edge of Russia, before turning, northeast toward the Aleutian Islands, another part of the Ring of Fire.  We follow these along the Bering Sea until we reach Alaska.  Then we follow the shore around until we head south into British Columbia.  Once we reach Seattle, we sail south on the west shore of the continental US to Los Angeles, and then down to Baja Mexico and on to Costa Rica.  Finally, we go through the Panama Canal (the opposite way this time) and head into the Caribbean Sea.  We sail northeast to Jamaica.

Year 16:

(Hazel route) From Jamaica, we sail past Haiti and on to the Turks and Caicos Islands before sailing on to the Bahamas.  We head up the west coast of the USA to New York, then continue north to Canada, first stopping in Nova Scotia and then Cape Breton.  We turn west at the Gulf of Lawrence, then head southwest toward Quebec City.  We pass by Montreal and end up Lake Ontario where we go counter clockwise around that Great Lake.  We exit into the Erie Canal and take the Hudson to New York City.  Our final sail is down the USA coast and end up in Florida to sell S/V Lynx, our circumnavigation and Ring of Fire voyage complete after sixteen years of adventure.

Monday, April 12, 2021

A Dual Diesel/Electric propulsion boat


A Dual Diesel/Electric propulsion boat

First of all, what are the types of propulsion?  Well, a hybrid diesel/electric boat is generally talking about electric propulsion with a diesel generator.  A diesel boat is using diesel motors.  However, a Dual Diesel/Hybrid is both.  That means, we have diesel engines and a electric motor system on board.

We will talk about two versions of a Dual system.  One uses pod motors (see image, top right), with separate diesel engines.  The other is a Parallel system, which uses diesel engines with an attached electric motor between that engine and the shaft drive (see image, bottom right).  The advantage there is you only need one prop for both the diesel engine and electric motor.

We know, you have some reservations.  But we understand the issues.  The main ones are the complexity of upkeeping and repairing two systems, the added weight, added drag, and the added cost to set them up in the first place.  These are all real issues.

However, let’s address each issue and why we may still go with a Dual propulsion system. 

The Issues:

1) Complexity

We can start with complexity.  In truth, having both propulsion systems is not that much more complex… really, we mean it, stay with us here.  If we compare a diesel boat, you have the upkeep of the diesels, and likely you have a generator on board as well.  Then, you have your electric system for handling all your needs, things like house batteries, inverters, shore power isolators, MPPT controllers for your solar panels, etc.  So, what would we be adding to this system to get electronic propulsion?  Not much.  Mostly, we are just increasing the size of elements that already exist.   A larger batter bank, a larger solar array, larger inverters.  So, the complexity is not increasing so much as the size.  We would be adding the electric motors, but those are brushless motors, so very little to go wrong or maintain.  Now, with pods, we must also add a hydraulic lift system, which is a little added complexity, but we will also have other hydraulic systems onboard already (steering, most likely, and autopilot rams).  Therefore, we already have to carry the things needed to repair hydraulics, so that is not adding much.  As for a parallel system, you do not need the hydraulics, and you reduce complexity by eliminating the saildrives.

2) Drag while sailing

If you have pods, the issue is having four props instead of just two in the water, which adds drag.  Our solution to this would be to put the two pod motors on arms that swing up out of the water when not in use, thus, reducing drag while sailing.  Easy enough.  Here is a picture of such a system that was for sale awhile back.  We will be making our own version of this, though very similar (these are not available anymore).  However, if you go with a parallel system, then you have a single shaft drive and prop for both propulsion systems, and eliminate the drag of a saildrive!

3) Weight

OK, now we are getting to the real issues.  Weight is a big deal on a catamaran.  Therefore, a Dual propulsion system is not going to work on just any catamaran.  You would need to have one that has a large enough load carrying capacity.  We plan to buy a cat with just that in mind.  Still, even on such a catamaran, you would still want to keep the weight as low as possible.  Therefore, if we go with pods, we would go with the lightest motors we can find, something like 41 pounds (each).  Of course, you need the arm and hydraulics, with adds more weight.  Still, this can be done for around 200 lbs, total.  
With a parallel system, you add only the electric motors and clutches, etc.  These add a bout 75 pounds each, or 150 pounds total, a little less than the pod system.

Of course, you must also add the weight of the large lithium battery bank.   However, it should be noted that we plan to add a large lithium battery bank for other reasons, like refrigeration, AC, etc.  And, we plan to have a larger solar array to charge these batteries.  We need these for all the other power requirements but the electric propulsion system can make use of them as well.  So, technically, all we are adding to the existing setup is the 150 to 200 lbs., depending on if we go with a parallel system or pod motors.  That is acceptable since we gain so many advantages.  We will go over these advantages further below.  But before we look at the advantages, let’s take a look at the final issue.

4) Cost

This one cannot be dodged, though it can be mitigated.  Let us explain.  As mentioned in the ‘Weight’ issue, we will already be adding the solar and batteries for other reasons.  Therefore, the added cost is only the pods and lift system for them.  Still, that is not an insignificant number.  The pods run $9,000 apiece and the hydraulic system another $2,000.  So, we are looking at $20,000 to add this electric propulsion system.  Ouch.  If we want to add a parallel system, it is even worse, as these run around $27,000 each (though this includes a brand new diesel engine).

However, now to the mitigation element.  That cost will be returned in fuel savings over time.  In fact, the pod motors will save us more than $85,000 in fuel and maintenance savings during our double circumnavigation.  If you want a full breakdown of why we save this much, you can read up on our website where we breakdown each passage to show the fuel savings.  As well as savings in gas, propane, maintenance, etc.   You can find that page here:


Advantages of a Dual propulsion system:

 OK, we went over the issues, now for the advantages! 

1) Fuel Savings

We already mentioned the huge fuel savings.  In most short or mid-length passages we will not even need to turn on our diesel engines.  With 3 hours of electric motoring available when we depart and regaining another 3 hours from solar along the way, we will seldom need to fire up the diesel engines.  And, on longer passages, we save more fuel (over a hybrid system) by having the more efficient diesel engines to run instead of using a generator and converting the power, which causes up to a 20% energy loss. Between the two systems, each having its advantages in certain situations to save fuel, we come out way ahead.

2) Less noise and smell

In most cases, we won’t need to use our diesel engines and that means that we don’t have to here them or smell them while on a voyage.  That is a big plus as neither of these are desirable.  We will have to live with them when it is necessary on a long passage, but those are few and far between compared to the massive number of shorter passages where we are noise and smell free.

3) Instant power available

Diesels have to be warmed up before use.   This wastes power.  When we are entering or leaving an anchorage, we do not have to fire these up and wait for them to warm up before using the throttles.  With the electric pods, we can use them as soon as we can drop them in the water (about 30 seconds).  If they are already in the water, they are ready to go.  Another use of instant power is during a tack.  Catamarans are great, but they can have a hard time in certain situations when you tack.  If needed, you can always push the bows around through the wind with a little bit of electric thrust.  And, since you do not need to warm them up, you can drop them into the water just before a tack, push the bows around, then just raise them back up to get rid of the drag.

4) Thrust at any RPM

Electric motors do not have a sweep spot in RPMs, like diesels.  With your diesel engines you have a minimum RPM that you need to keep them happy.  This works fine when you want to motor for long periods at 5-6 knots, you set them at around 1,800 RPMs and you are good to go with excellent MPG.  However, if you want to run them at a slower speed, that will not work.  With electric motors, you can do a couple of things.  One is maneuver in a marina without having to use higher RPMs.  This gives you better control of the boat.  Also, you can use lower RPMs while sailing to motor sail at lower wind times.  With a diesel, you would have to just drop the sails and go with the 1,800 RPM setting.

5) Drogue effects in heavy seas

While you are in large swells, you can use the electric propulsion as a drogue system.  You have the pods power you up a swell face, then spin backwards on the way down, slowing the boat slightly.  This evens out the speed of the boat, which is more comfortable (and safer since you do not want the bows to plow into the next swell at great speed).

6) Extra propulsive power when needed

This is an area where the hybrid system loses out to a diesel.  Generally, unless you are going to run four electric motors, the diesels have more power.  However, where power is really needed, in the case of a Dual propulsion system, you could run both!  That means, on our boat, we get 110 hp from diesel power and 60 hp from electric for a total of 170 hp!   You will not need this often, but there are situations where you need all the power you can get.  There are several emergency situations with current or lee shores, but here is another example.  From Koblenz to Wiesbaden, on the Rhine River, the river is running at nearly 9 knots.  That means you would need all the thrust you can get to make that 40 mile stretch of river.  We do plan to travel up the Rhine, across the canal to the Danube, and down to the Black Sea, to this is important.

7) Regeneration when sailing

While sailing, especially during high winds, you can use the electric pods to regenerate power.  This will not happen all the time, but on occasion, there is some energy to gain this way.

8) Less Maintenance (than a diesel boat, but not a hybrid)

How can two systems cause less maintenance than one?  Well, in the case of comparing to a Hybrid only boat, a Dual propulsion system has additional maintenance.  However, compared to a diesel boat, there is actually far less.  This is simply because we will be running the diesel engines far less often, which means less miles on them and longer periods between maintenance.

9) Redundant propulsion system safety

Backups on an ocean crossing boat is paramount, and with the Dual propulsion system we have another kind of backup, two methods of propulsion.  If we lose an engine, we can still fully maneuver in port with the electric motors, and visa versa if we lose electric power, we can still use the diesels.



If you are a boat that plans to stay for long periods in remote places (which we do), with a larger crew (which we will have), then you have greater electric needs in water making and refrigeration, at minimum.  Due to that, you need a larger battery bank and more solar panels to charge them.  Once you go that route, adding in the pod motors is not a huge hit in weight.  As for the cost, in the long run they will save you loads of money in fuel savings.  In addition, you gain all the comfort advantages from electric propulsion on the majority of your passages.  You also get the fuel savings of the diesels on long passages.  Of course, you need a boat that can handle the extra weight, so smaller performance cats are probably out.  However, if you are going with a 45-46’ comfort oriented, production cat, then this is a viable option with a host of advantages and very few disadvantages.  It would also be possible on a larger performance cat of at least 50' LOA.  Obtaining one of those boats is our plan and, unless we are convinced otherwise, this is the propulsion system we plan use on S/V Lynx.