Monohull verses Multihull powersailers / motorsailers

[brian eiland]

Hummingbyrd 62 Powercat

...here was my initial reply

I thought I would present the case for smaller vessels, and shallow draft vessels.

Let me precede this opinion of mine by stating that in the past I have lived aboard a 60 foot Chris Craft power yacht and a 47 foot sailing craft for 2 & 3 years respectively. I've moved up and down the east coast, cruised the Bahamas for 8 months, sailed down to St Thomas and St Barts on several occasions, and island hopped from Florida down to Venezuela. I also spent 13 years in the boat business on the Chesapeake Bay based out of Annapolis MD.

Most recently I have been exploring the possibilities of moving back aboard a vessel of some sort (maybe even a floating house) with my new wife from Thailand, for that portion of the year we will be spending in the USA. I'm having to brainstorm, what minimum size and type of vessel might meet our liveaboard needs, yet be affordable?? I'm looking at a variety of ideas, and a variety of used boats. I have always been a BIG fan of MotorSailers, and catamaran ones in particular, and if I could afford it I would be very tempted to build one of my own designs. But in reality most of my designs are just a little too big for an owner/operater couple,.... at least bigger than necessary, thus requiring elevated operating expenses, maintenance expenses, and dockage expenses. On the other hand the catamaran hull form does offer several great attributes....shallow draft, greater accommodations within a spacial distribution for privacy in a shorter length vessel,....and level stability that women love (very important).

So what might I recommend for your needs, Mick??

1) First off I would lead you to vessel of less than 60 feet. I think you should consider a vessel size that you can fairly quickly become acquainted with handling yourself. This will inspire your self-confidence to go exploring on your own (you and your wife), without feeling the absolute need for a third party captain. You can take your friends out for an afternoon or weekend cruise without feeling the need for an operator. (I once worked for an owner who specifically ask that I take vacation off the vessel when he came to spend time on the vessel with his wife).

2) As you are brand new to boating I would NOT suggest any sail power, although you may come to appreciate it in the future once you experience it on someone else's vessel. (have a peek at these two videos I just posted recently)

3) I would NOT suggest a new-build (custom project) until you've had a chance to experience some portion of your dream afloat and can make a more informed decision as to your likes/dislikes.

4) I would suggest a nice stable vessel, with a nice house size galley, and a comfortable bathroom (head as it is known). These features are very important for the liveaboard aspect, and they are VERY important for the lady (I'm assuming you really do want to make this dream last for at least 5 years...)

5) I would suggest a vessel with shallow draft and well protected props and shaft systems. The protected props and shafts will save you a lot of heartache and money when you make those few mistakes that many new boaters (and a few older ones as well) make on occasions.

I can't emphasis SHALLOW DRAFT enough. Here I am defining shallow draft as 4 feet or less. The Chesapeake Bay (America's largest inland water bay) has a few navigable deep water channels, but the vast majority of its area is 4.5 feet of water or less on average. If you truly want to explore the Chesapeake Bay and its many tributaries (one of the truly great cruising areas), you better have a shallow draft vessel. Ditto for the Outer Banks of NC (I once did them in a 37 foot sailing cat that I could kick up its CB's and rudders to draft only 24 inches). Its nice to have a shallow draft for the Florida keys, and the 10,000 island area of SW Florida, and those inside waterway passages of the west coast of Florida. Gunkholing is so much fun, and you miss some of this fun when your vessel draws too much water....you end up passing many delightful spots for fear of running aground.

If you are intending to do the east coast, then around Florida, you might well consider doing the popular 'Great Loop', up the Mississippi, to the Great Lakes, down the Erie Canal, etc.

And don't forget the Bahamas that whole chain of islands is structured on a shallow ocean shelf that is a delight to go cruising across rather than around, especially with those crystal clear waters. Shallow draft is king!

I started out to write this posting and make a suggestion of a few possible smaller vessels that I had recently become aware of...several of them being production mono-hulls. But as I read my own words, I can't help but think of this wonderful vessel I just spent a few days aboard in Palm Beach. It was recently purchased by a good friend of mine for his own liveaboard & treasure hunting purposes, so it is not available. I'll present a few details and photos as an example of what I consider a really nice liveaboard cruising vessel that is not too audacious while accomplishing most of what you have in mind plus a few extras...great dive and explore boat.

This is a 62' powercat that was custom built by an associate in wood/epoxy/composite. I'll post some pics I took while visiting. Look at the interior room available in this vessel,....and that great galley and big saloon. One master stateroom in one hull, and two guest staterooms in the other. Then how about the great aft deck and its additional galley, outdoor grill, and dining area. This vessel drafts 3.5 feet, and is powered by two 6 cyl Cummins engines of 210HP . It will do 17 knots while using a fraction of the fuel of many yachts this size. It is highly maneuverable with those twin props widely spaced apart. Its easy to get on and off the tender from those swim platforms, and in fact could easily carry two tenders (his and hers), or other water toys. It has a generator and a watermaker, and a highly insulated refrig box and freezer that only requires running one engine once every two days. Its self-sufficient. The cost...less than $1M. I envy his choice.

See what can happen in only 60 feet!! And you and your wife could fully handle this vessel by yourselves.

Regards, Brian

 

[brian eiland]

Hummingbyrd Powercat article in Multihulls Mag

And here is an article I had saved from an old issue of Power Multihulls. (attached PDF}

I had previously underlined a number of details in this article. Here are just a few excerpts I thought I might emphasize:

Fuel Usage:
"Total fuel burned was ninety gallons, a bit over one nautical mile per gallon. With a fuel capacity of 1500 gals Hunmmingbyrd could easily transit 1,200 nautical miles at 18 knots, and double that at 12 knots"

Shallow Water Speed:
"Entering the multi-hued, shallow water on the bank, I watched our boat speed increase 2 knots as the big cat began to 'feel the bottom'. Orrin explains the phenomenon. The hydrodynamic hull form produces a wave that provides lift when the water is twelve feet deep or less, literally pushing the boat forward. He pulled the throttle back to 1800 rpms and we maintained 18 knots. His experience shows that it is actually more economical to run the shallow waters of the ICW than to go outside due to this effect"

Rough Water Operation:
"Entering Whale Cay Cut I noticed the catamaran has a slightly annoying quick motion in a beam sea. The six-foot swells were piling into the shallow water, and they began to break across the channel. Orrin pushed the throttle up until we were motoring along at 18 knots, and incredibly the ride smoothed out. Orrin assures me that 25 knots is perfectly comfortable in any seas up to about 8 feet"

...and read that conclusion in the article

 

[Squidly-Diddly]

if it lifted their hull, why did my rowing scull's stern get pulled down

when running in proportionally shallow water?

Same with kayaks and canoes, so it isn't anything to do with sliding seat or oars.

"Entering the multi-hued, shallow water on the bank, I watched our boat speed increase 2 knots as the big cat began to 'feel the bottom'. Orrin explains the phenomenon. The hydrodynamic hull form produces a wave that provides lift when the water is twelve feet deep or less, literally pushing the boat forward. He pulled the throttle back to 1800 rpms and we maintained 18 knots. His experience shows that it is actually more economical to run the shallow waters of the ICW than to go outside due to this effect"

 

[brian eiland]

SAIL mag article

Interesting article I ran across in SAIL magazine that includes both monos and multis

Cruising Criteria: How to Pick the Best Cruiser
http://www.sailmagazine.com/cruising-tips/cruising-criteria

 

[brian eiland]

Reliving old boating experiences today. I sure wish I could have afforded this 62' foot powercat when my friend was selling it. Would have made a great live-aboard, and explorer.

See the info and pictures just above.

 

[brian eiland]

This was my answer to Mr Greg Jones:
Hello Greg,
Just finished reading two articles you wrote on motorsailers, and I can tell you are ‘hooked’ (to use a fishing term) on them as much as I am. Right up front I would like to compliment you on your “50% Solution” article. I liked it better than any other I have seen that tried to define this potentially very broad spectrum of vessels…..very comprehensive and fair as far as the monohull versions are concerned. You just left out the most modern versions based upon the multihull form.

I really can appreciate a lot of these new ideas in the ‘motorsailer theme’. I believe that many marketing people are waking up to the reality that the already small sailing population is on a decline and gravitating toward faster cruising forms in power and/or sail. Some of this is a result of the older population deserting sail for a trawler. Some of this is the younger population not content with slow cruising in this fast paced world….they may only have the weekends to work with.. I think some of the renewed interest in the motorsailer concept is the result of these observations…so they say lets add some more OOMPH in our sailboats. But be cautious, that does not a motor sailer make.

Adding a bigger and bigger engine (or twins) is not the most efficient solution, although it does more truly exist as a MOTORsailer. As you said, “A big engine will only mean you will be able to maintain speed in adverse conditions: You won't go any faster” I think you made a very important observation, “Accept that the virtue of a motorsailer is that you can make higher average speeds, which is done by eliminating the slow speeds and continuing to make decent way even in the absence of wind”. In other words bigger engines for faster top end speeds aren’t the answer in defining the monohulled motorsailer, even thought the marketing guys would have you believe so. And the real virtue of twin engines is maneuverability and ‘back up’ propulsion source. But wait a minute, in a motor sailer our back up propulsion source is the sailing rig, so twin engines is overkill in most situations.

I start to see a trend here similar to what is happening in the trawler world. There seems to be an increasing demand by the public for just a little more speed than that offered by the truly efficient displacement trawler. So now we see more and more twin-engined trawlers, with greater and greater HP, that in reality are going beyond the definition of trawler…they are becoming motoryachts in trawler clothing. (wolf in sheep’s clothing)

The crux of the problem is when we try to overcome some basic laws of nature in trying to push the monohull form pass its ‘hull speed’ in an efficient manner, whether power or sail. Sorry, but it just takes more power and some ‘planning surfaces’ to do it. Alternatively we can look at pushing longer slimmer shapes that exhibit less hull speed resistance. In the sail mode we have to space these slimmer hulls apart some considerable distance to get stability to carry the sailplan. In the power mode this wide separation is not required necessarily.

In the ever-continuing effort to define the term motorsailer, I particularly liked your Supreme Court Justice quote, “We know it when we see it”. I think this is particularly applicable to the increase in both sailing and powering performance available with the multihull planform over that of the monohull. There are still many boaters that are unwilling to accept these very compelling attributes. As you said, “today's motorsailers are evolving quickly, driven by more knowledgeable owners and designers who derive inspiration from the best boats of the past and improve them with modern design technology and a sure eye.”

Two of the most innovative monohull vessels I’ve seen that take efficient cruising into mind along with increased performance would have to be Chuck Paine's Steadysailer <http://www.chuckpaine.com/zsteadysailer.html>
and Steve Dashew’s FPB (fast pilot boat) series <http://www.setsail.com/dashew/do_PARADIGM.html>
Dashew’s vessel is not a motor sailer as it has no rig, but it is an honest attempt at efficient cruising under power. Here also in the strictly power category the multihull form will present a formidable challenge to the monohull form….just look at the variety of power cats already unfolding.

I believe I have already referred you to my forum posting, “Monohull verses Multihull powersailers / motorsailers”,http://boatdesign.net/forums/showthread.php?t=4499 that starts with a discussion of the Powersailer 20 from New Zealand. Much further along in this subject tread at posting #76 I introduce my observations on the big new MITseaAH
motor sailer http://boatdesign.net/forums/showpost.php?p=45367&postcount=76 . Within this same tread discussion there is another particular posting you might find interesting, “A Liveaboard Cruiser For The Real World” http://boatdesign.net/forums/showpost.php?p=35945&postcount=27


And then I’ve attached another letter I wrote just recently to a gentleman who built a big monohull Rivolta 90 motorsailer http://www.rivoltamarine.com/rivolta90statement.html
In brevity I submitted to him, “When I review all of the virtues you sought for your Rivolta 90, I find I can accomplish all of these same virtues in my 65' catamaran design…..And with half the sail area, considerably shorter mast, less engine hp, less complicated keel arrangement, etc, etc. Thus the building cost/selling price of this vessel should be considerable less”.

Cheers, Brian

I'm reading back thru this old subject thread of mine, and I thought this posting needed to be repeated,...
...particularly when i just looked thru the latest issue of BOAT International that hi-lighted 'Catamaran Spectacular',...such a group of big ugly new cats, particularly powered ones !

 

[brian eiland]

So I guess we don't have many Motor-Sailer fans in this new boating world? ,....what a delight they can be for a cruising lifestyle or live-aboard.

MotorSailing Synergy (Bob Leask said)
Motorsailing offshore is by far the most pleasant way to make passage, most of the time. With the engine barely above idle and a moderate amount of sail set, there is a synergy created by the apparent wind which generates more forward thrust than either one alone, with the bonus that you don't have to set large areas of canvas, which will have to come down in a hurry if the wind increases. The boat rides better, makes a better average speed and the batteries are always full. The benefit of using a much smaller sailplan can only be appreciated by someone who's been caught offguard in a squall with too much sail up. "Adventures" like that might be fun for weekend sailors and short coastal passagemakers, but on a long ocean passage they're something to avoid, even if it means a slower passage.

'In light airs, running one engine often is all that is needed to bring the apparent wind forward to make the sails work harder, and the combination provides much better results than either motoring or sailing alone…… sailing synergy/harmony, the motor taking over in the lulls and the rig taking over in the puffs'

 

[brian eiland]

Sail-Assisted Trawler/Power Cat, BAMBA 50'

Here is another sail-assisted power cat that looks to be a real comfortable live-aboard, go anywhere motorsailer. and it happens to sport an optional sailing rig, an AftMast one at that.

Lets see I think I've touted both of these ideas,....aft mast rigs, and motorsailing catamarans....

BambaYachts - individually built and with external project management

I think I even detect some sort of wave splitter up front?

 

[Paul Scott]

#262 lays out important points. If I might add some things, given our experience with a refit 10Kw 48-5000 electric battery 12.0 Torqeedo saildrive in an early class 40 ish monohull over the past couple of years: which has led me to think an electric motor sailer should have:

- ultralight construction

-very clean aerodynamics- it doesn’t take much to slow her down when under purely electric power - maybe a wing mast that can be stowed flat easily and quickly raised? (Probably need an unstayed mast to pull that of cleanly?)

-low wetted surface and wave making drag for the regime under hull speed, and possibly a slightly lower prismatic for this lower speed work

-enough surface area for solar panels integrated into the deck and cabin to generate real power without the need for external bulky mounting structures

-terrifically close winded hull and rig (apparent wind games)

-able in very light winds- furling code/yankee zero, for example, high AR in a sloop rig, or an unstayed, easily reefed una mast rig. (See pic above & below for a general idea of a monohull approach)

-an electric outboard (outboards?) might be best- so it (they) can be pulled out of the water when only sailing, and consciously lowered into the water for regeneration or propulsion, since regen does take a knot or two off of sailing speed.

To sum up, a motor sailing electric boat is like sailing, except more so- you’ve got to play wind, current, tide, sunshine, battery charge, course & waves exquisitely, even delicately. Although possible to do this intuitively, automation might be needed to appeal to a general audience, which will make things really expensive, to say nothing of current styling trends that are high aero drag, weight, and the need for speed, which lead to big engines, big batteries, and big superstructures, as the trawler cat above.

I really do wonder if electrical power fits into a world where virtually unlimited power has pushed boat design?

 

[brian eiland]

How about this motorsailer,..the 70 foot Saphira,....
Look what this older couple have come up with ! performance, ease of handling, and safety

Here is a very interesting story of the development of this vessel
A Dream Takes Flight | Cruising World https://www.cruisingworld.com/people/a-dream-takes-flight/

And I imagine that the up-keep on this vessel could be far less than many comparable vessels,....only 2 sails, minimal rigging, two nice size engine rooms, etc, etc

I am totally impressed !!

 

[brian eiland]

Sail-Assisted Trawler/Power Cat, BAMBA 50'

Here is another sail-assisted power cat that looks to be a real comfortable live-aboard, go anywhere motorsailer. and it happens to sport an optional sailing rig, an AftMast one at that.

Lets see I think I've touted both of these ideas,....aft mast rigs, and motorsailing catamarans....

BambaYachts - individually built and with external project management

I think I even detect some sort of wave splitter up front?

Update:
Can't find that PDF at this time, but found some other sites with brief mention and more photos of her:
Boat Review by Multihulls World of: Motor Bamba 50 - Multihulls World https://www.multihulls-world.com/review/motor/bamba-50-sail-or-engine-the-choice-is-yours

Performance & Range: Powered by twin 150 hp engines, designed as a long-range cruising trawler capable of extensive ocean transit (such as an Atlantic crossing) under power or augmented by its furling genoa.

Capacity & Tanks: Accommodates up to 8 guests across 4 double cabins with 2 heads (or up to 4 staterooms in the hulls); carries large tankage including up to 4,000 liters of fuel and 800 liters of water.
****************

BAMBA 50: Catamaran Motorsailer - Wave Train https://wavetrain.net/2012/04/23/bamba-50-catamaran-motorsailer/
Yo peeps. I’m tapping this out in the wind-blown town of Lorient, France, where I spent all day yesterday browsing through a small, but very interesting boat show, Les Salons du Multicoque. This is a special presentation of multihulls, containing some very cutting-edge boats, that flops back and forth between Brittany and the Med. Ironically, one of the boats I found most interesting was this new Bamba 50, a catamaran motorsailing trawler built right near here in La Rochelle. It serves as a trenchant reminder that the “edge” in boat design can cut more ways than one.

The mast is quite tall (air draft is about 60 feet), is set well aft, and is designed to fly either one big 860-sq.ft. genoa or a 1,075-sq.ft. gennaker.

Check out that funky sailplan profile

The motive force of the sail augments that of the engines, two 150-hp Iveco truck diesels that are configured to run at low revs (max rpm is 2,800, and they cruise at 1,400). Carrying a smidge over 1,000 gallons of fuel, the mighty Bamba reportedly has a functional range of over 3,000 nautical miles under power alone, which, of course, can be significantly increased by simply rolling out the sail. In motorsailing mode, I was told, the leeward engine runs alone, turning just 700 rpm.

Play your cards right on this boat, and I reckon you could easily get through a full season of cruising–or maybe even all the way across the Atlantic and back–with just one trip to the fuel dock.

Accommodations, of course, are astoundingly palatial.

The saloon looking forward

The spacious flybridge

Picture windows in the master stateroom aft

A pair of clever bunk berths in the smallest of the three guest staterooms

A well-appointed galley

On the dock at the show

At anchor in the brochure; note the fold-down transom

What you’re looking at here is hull number one, which was built on spec. Bamba is actively seeking representation in the U.S., has worked out a design for a big Bamba (60 feet) and (thanks to several comments received at the show) is currently drawing a baby Bamba (approx. 42 feet) on the back of the proverbial napkin.
*******************************
Bamba without a sailing rig:

 

[brian eiland]

Bamba hull has hints of Tennant's hull designs

 

[brian eiland]

shallow water capable,..

 

[bajansailor]

That Bamba does look very nice indeed.
However when I clicked on the link for the website, it is not working - I hope that they have not gone out of business.

 

[montero]

In the case of motorsailer catamarans, size certainly matters in terms of the risk of capsizing.
Perhaps a trimaran with folded amas could be self-stable?