Trinkatoo

Author:
Publish date:

When Alan Saunders wanted a multitasking tender, he decided to take matters into his own hands and created an electric sailing tender that was reliable, easy, and stable. Follow along as Alan creates a charming dinghy that's not only efficient, but lots of fun! All too often have I gone on cruises where, on arriving at an anchorage or marina, the activities were limited to conversation, munching, and of course a drink or two, be it ashore, afloat, or both. Mind you, I have nothing against conviviality and boat slumming, but to me, neither qualifies as powerboating. For that I need to feel a vibrating deck, to hear the smooth hum of her engines, and to experience the glorious sense of power as her bow parts the waters in her path.

Once in a mooring field—or worse, deep in a raft-up—it's hard not to feel a twinge of longing for the little sailboats one sees tacking merrily to and fro. But the idea of being totally dependent on the whims of Mother Nature has held back many from setting forth aboard an engineless tender. So, I have sat atop many a bridge and in countless saloons, club bars, and restaurants and enjoyed the company and tall tales of others. I've laughed, raised my elbow, and hoisted a few with the worst (the best were way out of my league) and otherwise been a reasonably good fellow cruiser.
What those hours awakened in me was a long-dormant desire to own a sailing tender that could go careening amongst its senior brethren for an hour or two before or after the social mixer, a vessel free of outboards and without the reek of gasoline or a willful rope starter. And when push came to shove, I wanted to be assured that I would be able to return to my vessel pretty much on schedule regardless of wind or tide. That would make my day.
To achieve my secret desire, I would need a dink capable of doing all the purely utilitarian tasks that my venerable Achilles inflatable had hitherto performed, and then some.

A MULTITASKING TENDER

My answer, I decided, lay in an unsinkable tender that could do a good job of sailing, rowing, and powering and could safely hang off standard stern davits or be easily hoisted aboard. Not only that, this dinghy must also be capable of switching from mode to mode without fuss or bother, and do it so seamlessly that children could be entrusted with her. She would need to be fast, fun, stable, lightweight, and sturdy. She would have to have good lines (for a well-designed vessel is a pleasure to behold), be easy to right, handle well in a chop, and ferry four crew with no trouble. All in all, rather a tall order.
After a long and fruitless search, I found the beginnings of my answer in a Bauer 10, a beamy, 10-foot dinghy made by Christof Bauer's Bauteck Marine of St. Augustine, Florida. In designing and building her, Bauer put together an elegant and unsinkable fiberglass tender, a vessel that sails nicely with main and jib or with a gaff rig, a boat with a self-tripping centerboard and tip-up rudder. (The latter combination makes rowing or beaching her a gentle and smooth maneuver.) In addition, she powers well with a small outboard. My Achilles, like most inflatables, lacks a keel, so rowing her can be an exercise in frustration in anything short of a dead-calm surface, never mind hoisting a sail.
The wise and only alternative to gasoline, with steam and nuclear being out of the question, was to go electric. On accepting the use of electricity as motive power, two basic mounting choices became available.
· Choice A: Get a stock trolling outboard of appropriate power anduse itas is. Hang it on the transom, connect it to a battery, and go. This was the simplest and cheapest option.
· Choice B: Fabricate a new housing, incorporate the motor, and glass it in as an integral part of the skeg or the aft end of the keel.
Choice A was rejected out of hand. Stowage of the motor, shaft, mounting bracket, and controls pod would be a constant problem. Also, when deployed, the array would interfere with sailing gear, so my basic full-time, multimode feature (sail-row-power) would be defeated.
Choice B, the built-in approach, was doubtless a more complex process, but with it, all three propulsion modes would be available full time, and this was my foremost requirement. Further, it would not preclude the use of an outboard for towing another vessel or at times when a much higher travel speed was desired. These, of course, are the occasions when a gasoline engine truly shines.
I selected Choice B, despite its shortcomings of higher cost (nearly all of it in labor) and its demand for some skilled glass fabrication and gelcoat work.
For my motor, I chose a 54-lb.-thrust MotorGuide saltwater unit, the most powerful motor I could find at 12 volts. Of it, I kept only the motor and its stainless steel shaft. Five or 6 knots was my motor-driven target speed, modest compared to what a gasoline unit can deliver, but ample for my tender's triple-threat needs.
For my "fuel tanks" I opted for a pair of no. 24 Deka deep-cycle, 73Ah gel-cell batteries. Even though gel cells are considerably more expensive than wet ones, they last longer, are sealed and spillproof, require no maintenance, and are much more tolerant of low temperatures, shocks, and vibration. I definitely liked all that. Thus equipped, Trinkatoo gives us a cruising range of about two hours at full power or well over 5 nautical miles, depending on load and conditions. Not only that, but the total added weight of the entire electric-propulsion components package comes to slightly over 120 lb., leaving my tender well within the 300-lb. limit of most davits.

PUTTING HER TOGETHER

My first step was to break up the boat's original continuous flotation compartment with bulkheads. I created four sections: two amidships to house the batteries, one fore, and one aft for storage. The battery housings are situated at her beamiest point, where they maintain proper lateral weight distribution as well as good fore-and-aft hull balance. All new openings have gasketed access hatches and are screwed down and sealed with 3M 101 polysulfide to keep them watertight. The forward hatch holds a mushroom anchor and its rode, plus lines and fenders. The aft one houses the boat's controls, plus some stowage room.
The first and arguably most important step in creating my "inboard electric tender" was fabricating the new housing for the motor. We began by splitting lengthwise a 15-inch-long piece of 4-inch PVC pipe to make the mold. We waxed the insides of the two halves to keep the fiberglass parts, once they catalyzed, from sticking to them. Only after the waxing was done were the roving and chopped fiberglass mat inserted. Resin was then applied and smoothed on with a narrow steel roller. Once cured and mated, we slid the resulting glass cylinder out of the mold, trimmed it to size, and bonded it to a glass cone that earlier had been similarly treated and fabricated over the motor's nose section. The new bullet-shaped assembly forms a loose-fitting sleeve over the motor. This provides a space for water to circulate freely within the housing so that it can do its motor-cooling job.
Next came the task of cutting a path for the shaft-mounting extrusion atop the cylindrical motor housing. We bonded a shortened, horizontal tunnel to make it possible for the motor and its shaft extrusion to exit and reenter as needed. Easy motor access for maintenance or replacement was an important element of the design.
Because the motor came complete with its own steel prop-protecting fin, it was a simple matter to carve a corresponding entry slot at the bottom of the new housing. The next step was removing most of the Bauer 10's skeg to make room for the new integrated power assembly. With that done, it was a simple if time-consuming matter to glass and fair in the new housing to it. Cooling water inlet holes were drilled well forward on both sides of the housing before gelcoating the whole assembly and installing a zinc anode.
The stainless steel shaft that carries the battery and control wires to the motor was cut down to fit inside the newly created stern flotation compartment. Access to it was made very easy through a new 12-by-10-inch hatch installed directly above it, thus turning that space into a small but usable locker as well. A 1-by-6-inch PVC pipe bonded to the hull became a through-hull for the shaft. Once screwed into the motor's extrusion, the shaft was held in place with a 6-inch length of automobile heater hose and four clamps (one pair clamping the PVC pipe, the other pair securing it to the shaft). To eliminate any chance of water entering and damaging the motor, the open top of the shaft was sealed with a healthy dab of silicone. This completed the propulsion package installation.
Next came the installation of the infinitely variable speed/forward-reverse controller. This is mounted on the forward wall of the helmsman's seat and close to the boat's centerline. Below it is a kill-power "crew overboard" switch, and inside the compartment there is a hidden on-off-on battery selection switch so only one is ever engaged. (The center position is meant to discourage unauthorized joy rides.) Completing our controls array are a power-inlet plug for a battery charger or solar-array feed, a 12-volt accessory plug for tool or device charging, and two voltmeters that serve as our individual "fuel gauges."
Early sea trials were conducted with more than 450 lb. of crew aboard, no sails, and 2-foot seas. We established our speed by hailing a 34-footer under sail. Her skipper said his vessel was making 5 knots as we easily passed her. (Yes, we were on the same heading.)
The prop is two-bladed and fixed. To limit drag, the prop can be made to settle nicely in a minimum "up and down profile" while we're under sail or rowing. Maneuverability and responsiveness in all modes are excellent.
For rowing, the Bauer 10 comes with a pair of beautifully finished 7-foot spruce oars, complete with permanently attached bronze oarlocks and leather wraps. Another nice touch is the lockable oar holder (also bronze), which, when securing the oars, also locks the bow compartment. Thus, valuables placed in a waterproof bag can be safely stowed there.

ENJOYING TRINKATOO

So, at a recent raft-up where munching, chatting, and drinking were the staples (not necessarily in that order), a fellow who owns a trawler started asking me questions. Not about tales told, but about what he called my "nice water toy." At first I bristled at the term, but then, on hearing a yearning note in his voice, I realized he had meant it as a compliment. I went on to extol Trinkatoo'scharms. After all, I reasoned, with more like her afloat, impromptu sailing dink races might become an option at these raft-ups. Besides, I believe in the heart of every powerboater there is a longing for a go at sailing—a longing that is usually stifled by the thought of being left entirely at the mercy of nature.
There are few better methods of understanding and learning the ways of the world afloat than with a sailing dinghy. Unlike most tenders, Trinkatoo offers not only safe and silent transport home for kids (and adults) when faced with confusing winds and tides, but also a very discreet cover-up for the means of that heroic return. I leave to one's own conscience if and when to make the disclosure of her secret propulsion mechanism to a puzzled audience. That, of course, also depends on how long that new sailor can keep a straight face.

About The Author
Alan Saunder's published books include George C. Marshall, A General for Peace,The Invasion of Poland, 1939; plus Radiant Floor Heating, and his latest; Beyond the Locket, an allegory of a little princess set in the Middle Ages. He is currently at work on a history of mercenaries, and on a survival guide for the divorced man.
He has also written for such magazines as National Geographic, Readers Digest, Better Homes, and Family Circle. For Popular Mechanics he did a cover story on deep sea diving where he explored the bottom of the sea aboard a three-man submarine. His boating articles have been featured in Southern Boating, Canadian Yachting, Northern Breeze, The Mariner, and Santana.
Alan is an avid sailor, tennis player, horseman—and a lover of books and good cooking. He lives hard by the sea in North Carolina.

Related