VOYAGING UNDER POWER-CATAMARAN
July 5, 2013
Panama City, Panama
The book that has been our “bible” for the last 20 years has just been revised. I mean Robert Beebe’s Voyaging Under Power has just gone through a thorough updating. This historical compendium of Passagemaker sea sense was first revised by Jim Leishman in 1994 as PAE was launching its highly successful NordhavnYachts designs. But at the time, no true passagemaking power catamaran was available. Well, my friends, the time has come for certain powercats to be recognized as full-fledged passagemakers. In this Fourth Edition, Denis Umstot introduces the MalcolmTennant Catamarans, with full feature of the DOMINO 20 design. At last, the gospel that Malcolm Tennant preached and that we enthusiastically spread along our travels is being heard.
Long-range power catamarans are a desirable cruising option.
Kudos to Umstot for having the foresight and courage to go against the grain of conventional and sometimes obtuse thinking about powercats!
As pleased as we are with the recognition of DOMINO 20 as a successful passagemaker, we’d like to address some of the comments in the book. The author obviously studied Malcolm Tennant’s blueprints but never came on board to inspect the finished product, therefore was not aware of the few modifications we made to the design. Neither was he aware of the specifics that we asked of Malcolm Tennant during the design phase. So, with all due respect to Usmstot, let’s expand on his very valid critiques of the design.
|Domino's Master Stateroom|
Conventional thinking has it that a 20-meter yacht should have at least 2 full staterooms with en-suite heads, preferably 4 staterooms. That was not our mandate and I have expanded on this in a previous blog. In keeping within the Robert Beebe “Passagemaker” philosophy, we wanted our stateroom to be large and comfortable, to have it at deck level, and not to give up “our” space for guests who might or might not materialize. Additionally, we refused to give up the forward hulls for accommodations, wanting to keep plenty of volume "for the boat" as Malcolm used to put it. Our DOMINO is made just for a couple cruising FULL TIME with occasional guests, mostly family who don’t mind sharing the head. Our thinking was, only one head, one shower to clean, one toilet to be maintained or unplugged (which happens every time we have guests on board.)
|Top bunk, 2-meter long, with large cupboard, lighting and ventilation|
Indeed, we could have lowered the bed to have more headroom
|The bottom bunk also has 2 full lockers,|
lots of headroom, but less ventilation
Our double-bunk is adequate for a couple and 2 children. Granted, we could have done a better job at designing the bunks, using the wingdeck space.
This modification has been well executed by Bill Shuman on his HERO powercat just launched in Pensacola. It can be done; we just didn’t want it, in keeping with our promise to Malcolm not to alter his design, not to widen the hulls, not to remove any bulkhead, and to follow his specifications and blueprints to the letter.
|Hero Powercat guest stateroom|
Visitors are, in fact, rare since we cruise far away from home and our guests so far have been more than happy to “tough it out” ... or we might give up our own stateroom once a year...
2 – Engine Room Access –
|Engine room access is well protected, within the cockpit|
The original fore-aft orientation of the opening has been turned 90° (athwartship) to use the curve of the wingdeck for the building of full stairs, at a 65° slope, with natural hand-grabs all along.
The stairs end in the pre-engine room where all the fuel transfer systems, filters and gauges are located.
A fireproof, soundproof door separate this “anteroom” from the engine room itself. We have had to access the engine rooms in rough seas and it has been very safe to do so.
We’re rarely seen a catamaran (or any small cruising yacht) with such safe engine room access.
|Wide steps, gentle slope, natural hand-grabs all along|
|Even at 85', the French PELICANO only has straight ladders to access the engine rooms|
3 – The Helm Bench -
|Grand son Asa shares the helm with his "fafa"|
|Plenty of foot rests and rails at various levels for added comfort and safety in strong seas|
So we went for the original bench design which, thankfully, presents a few advantages. The lack of metallic part in this all-wood bench has allowed us to place the gyrocompass under the bench, far away from all electronics.
JP built the bench to accommodate the largest sized paper chart, so we can store all our charts, pilot charts and other oversized documents without having to roll them. The bench inside dimension is 37” deep x 49” wide.
On long passages, the helmsperson has the option to sit sideways, stretching his legs on the bench. Alternatively, the bench backrest could have been built on a swivel, allowing to flip it forward and provide additional seating while at anchor.
4 – Flying Bridge –
|Dinghy storage aft of the arch|
|Grand daughter Maddie lazing while going down the East River, NY|
Indeed, we enjoy this large space very much.
|Paraguayan friends Daniel & Malou celebrate the New Year from the top!|
Not only do we store the dinghy during long passages, during intense fishing trips, at anchorages reputed for outboardtheft (Trinidad, Panama, Honduras) or to do all outboard maintenance work, but we love the sunset views from the top.
As for “getaway for crew members,” well, we don’t ever have crew members, so that does not apply to us. However, we keep in mind that the flying bridge can easily be modified and fitted to accommodated more entertaining and crew.
|MTD "RHUMBA", an Oyster Bay design, has fully-enclosed flying bridge|
This was successfully addressed by RHUMBA (a MTD Oyster Bay design) and HERO (another MTD design for Bill Shuman.)
|Bill Shuman's "HERO" has a hard-top flying bridge with excellent seating|
5 – Range – Malcolm Tennant was always very conservative with his numbers and estimates. He designed the DOMINO 20’s range with a goal of 4,000 nautical miles at 10 knots. After traveling almost 20,000 NM, we estimate that at 10 knots our true range is closer to 6,000 NM.
Here are the numbers at full load of fuel and water
RPM GPH SPEED (Kt) RANGE (NM)
|DOMINO under full load at the Myrtle Beach Yacht Club (Photo Philippe Dufour)|
It may, to some, seem silly to have such a large range capability. However, this allows us to select our refueling points, eliminating the dubious and risky drums and old barrels. So far, we’ve never had bad fuel. With the help of Tony Athens (Seaboard Marine and Boat Diesel.com) the tanks, fuel fill-up and transfer system have been designed to avoid ingress of water and condensation. So far, we have not had a drop of water in our fuel, which allows to keep fuel for a long time without using additive (16 months from Myrtle Beach to Panama City.) Finally, is the economy due to DOMINO’s highly performing John Deere 6081 engines? Possibly. Do we always cruise at 10 knots? Most of the time, we do so because we are trolling. Sometimes, we troll at 7 knots on 1 engine only (900 rpm, 7.3nm, 1.8 gph, 12,000 NM range.) At times, and DOMINO much prefers this, we cruise at 20 knots (2,000 rpm, 23 gph, 2,200 NM range) as we did to escape Hurricane Tomas, cross the Gulf Stream, or even to please our pilot on the Panama Canal. Bottom line, in our 19,000 NM of travels we have averaged 10.5 knots, 2.5 mpg.
Again, we asked to design our DOMINO with economy in mind, in keeping with the original “Passagemaker” philosophy: a boat for 2, cruising full-time, far-far away. Modifications would be easy. Our in-hull workshop could be scrapped to build a stateroom, for example, but I’m not about to take this workshop away from JP. If the galley makes every cruising woman want to move on board DOMINO, the workshop has their male counterparts salivating in envy.
For JP and I and considering our cruising style and destinations, DOMINO is, indeed, the Ultimate Passagemaker.
Thank you, Denis Umstot and Bill Parlatore for being such strong supporters of the Powercat concept in general and of our DOMINO 20 in particular. This is an idea that has come of age. Eight of Malcolm Tennant’s powercats have crossed oceans on their own bottoms. After the success of the DOMINO 20 design, as proven by the frequent New-Zealand to Samoa crossings of our sister ship TABBY CAT, we are so excited to see that Northland Contract Boatbuilders is now offering a small series of DOMINO 20. We wish them and Anthony “Tony” Stanton all the success they deserve.