by Milton Pierce
Here’s an easy way to eliminate the pounding your boat takes in rough water and get a consistently smooth ride.
You can imagine my consternation when I found that I couldn’t run my 16-foot aluminum boat more than five m.p.h. with a 75-hp. outboard. The boat performed beautifully on small lakes around my home in the northwestern part of New York state, and I had looked forward to family cruises and fishing trips on Lake Ontario. My first venture on the big waters was most discouraging. A brisk wind had piled up a rough chop. When I opened the throttle to normal cruising speed, the hull began to pound alarmingly. At less than planing speed, the stern would plow, aggravating the pounding. Finally, about 5 m.p.h. proved to be the easiest on hull and passengers—-scarcely worthy of a 75-hp. power plant. A few discreet questions among boatmen and a little research turned up reassuring answers. The problem is commonplace and the boating industry has the answer: trim tabs. Installed on the transom of a flat, planing hull, the tabs lift the stern when they’re depressed. The bow will then be held into the waves instead of rising over each crest. The best systems allow you to adjust the tabs to the optimum angle while you’re under way. With trim tabs, a small boat performs more nearly like the deeperdisplacement hulls used for sailboats. For experimenting with my hull, I wanted an inexpensive way to make the tabls, and I decided on a motor-driven hydraulic pump and double-acting hydraulic cylinders--of the kind used to rais and lower an automobile's convertible top--as the means for adjusting the tabls. I found the parts for my adaptation in an auto wrecking yard, complete with hoses and a remot-control dashboard switch.
HOME PAGE
