By Jon Blaicher
The idea of moving to a larger boat is often driven by the associated benefits. More comfort and more room for more people, food and drink are often at the top of the list. It isn’t until the first sea trial that the realization you might have to dock a much larger boat than you are used to, finally sets in. An unfamiliar boat in an unfamiliar slip can be frightening, especially when it is significantly larger than the boat before it. I personally experienced such trepidation when moving from a 28-foot express cruiser to a 40-foot sedan bridge. Like many a boater, I had bought into the folklore that a twin engine shaft-driven boat would be much easier to dock than my stern-driven express. Quite often I’d hear “You can dock with the throttles alone”, or “It’s easy, just don’t ever touch the wheel.” Huh? My analytical left brain kept reminding me that the larger bridge yacht was 3-feet wider, weighed three times as much with at least double the windage compared to our previous express. Can a couple of shafts and rudders really circumvent Newton’s third law? To hedge a little, I had the marina move us to an end slip, where we would only have to contend with one dock and no neighbouring boat. Luckily an end slip was available, and the longer walk was certainly worth the effort while I built confidence in docking the big sedan. As it turned out, docking with shaft drives was a touch easier, but only if I stayed ahead of the wind and managed to get a bow or stern line on the dock cleat quickly. Larger diameter propellers located 3 feet inboard, combined with wider spacing on the hull meant fewer corrections and less throttle was required to turn or pivot the heavier boat. But… shaft propeller net forces are predominantly longitudinal – forward and aft only. While you can use the propellers to move the bow to port or starboard by putting one engine in forward gear and the other in reverse, the stern will inevitably be pushed in the opposite direction of the bow. Thank you, Sir Isaac! Nothing a few 28-inch fenders and a hundred hours of docking practice can’t fix. I’ve also heard momentum can be your friend and that is true, but only once. If the wind picks up, all bets are off.



