By: Bill Jennings
There are several driving techniques that will result in a higher top end speed for your boat at no added cost. Here’s one of them.
Have you ever noticed while boating in a cross wind that your boat leans slightly into the wind? Ever wondered why it leans into the wind, when you would think the wind blowing on one side would lean it in the direction the wind is blowing? Here is the explanation.
Let’s say you are boating towards a destination and there is a wind on your portside. Your steering input has kept you pointing towards your destination, but what you may not realize is that to keep your boat heading to that destination, you have unconsciously applied a very slight steering input to the left, or portside to offset the wind push. This input causes your lower unit, or rudder, to move as if it is making a shallow left turn. This shallow turn prevents the wind from pushing you off course, but because your boat always leans into a turn, you think your boat is leaning into the wind. But this lean is the turn, not the wind.
Here’s the problem: when your lower unit is turned, even slightly, there is added drag. In other words, with the application of steering input to counteract the crosswind, you have unknowingly added drag. This drag will continue as long as you are applying a wind correction in order to travel directly to your destination.
Here is the good news. You can easily eliminate this lower unit drag. When cruising on a calm day and your steering is dead centre, place a narrow band of tape, top center on your wheel. The next time you encounter a cross wind, point your boat a few degrees upwind of your destination. Then straighten your wheel. The tape should be at the top of the wheel. With your steering straight, drag is minimal. But without a counter effect for the wind, your boat will not track to the upwind heading but will “crab” in a sideways motion to your destination. Crabbing replaces steering input and your boat speed will be greater. With a little practice you can quickly figure how many degrees upwind to point.
To determine how much drag is created when steering to maintain a true heading, Randy Scism, President of Marine Technology Inc, and I set up the above scenario while watching a GPS speedometer. Heading in a single direction with a 15-mph crosswind and gentle steering added to hold a true track, we ran a steady 109 mph. We then crabbed into the wind and straightened the wheel. Our speed jumped to 112 mph. Even if your boat will not run over a buck, Randy assured me that his experiments with runabouts running at slower speeds proved there is an instantaneous gain of at least 2 mph. Well worth the exercise. #tips #quicktips