Speed 101: Turning
Both classes began with basic boater safety training and the “Rules of the Road,” aka the International Regulations for Preventing Collisions at Sea, or Colregs. Before you can fly, you have to learn to walk.
Hull dynamics, and how they affect a boat’s handling, came next. Donzi builds monohulls so Barrie focused on V-bottoms, but Tres Martin’s curriculum covered cats and their distinctive traits as well. The schools had other differences, but they both stressed one of the most important skills to master at speed: turning.
“No V-bottom can turn safely in excess of 70 mph,” Martin said from the lectern.
“That may be true for some boats,” Barrie said during our later tests, “but I set mine up myself and am confident in its turning ability.”
So how do you safely turn at speed? Tres Martin has a special technique.
“You need to monitor your tach,” Martin said, “because the first sign of instability will be one tach spinning up beyond the other.” Turbulence around the hull is interrupting solid water flow to one or (with twins) both of the props — a sure sign things are about to go wrong in a hurry.
“In stepped monohulls, the engine inside the turn is most apt to lose its bite,” Martin said. “In cats, the outside one more frequently loses bite.”
For both Barrie and Martin, setting up for the turn is as important to its flawless execution as actually making it. The steps are deceptively simple.
To set up or “get set,” do a head pan to check for other traffic. Pull back slightly on the throttle. Martin repeats again that he wants you under 70 mph before the maneuver.
In Martin’s turn, hands on the helm at 3 and 9 o’clock, he executes the turn by rocking the helm 180 degrees then returning to center repeatedly — that rotation changes depending on the steering ratio of the helm. You’d expect the give-and-take turn to be jerky, but in execution, all three students managed smooth, flawless, aggressive turns from 50 to 70 mph.
Martin said that method better aims the boat and keeps the props hooked up in clean water. Craig Barrie uses a different technique.
“Slow down, check around, then feed a half-turn to the helm, then a little throttle,” he instructed me. I gave the helm 90- to 180-degree twist and fed in some gas. The boat steadied in the turn.
“Now, if you want to turn sharper, add more speed.” It seemed counterintuitive, but as I added throttle, the boat arced tighter and I edged the speed up, keeping one eye on the tachometers — both holding steady at equal rpm.
What if one tach suddenly ran up to the red line — or worse, you felt the boat slip loose at the stern?
“Your escape plan is always go straight. Never yank the throttle back. Go straight, get control, then ease back to a comfortable speed and collect your wits,” Martin advised.
Even a PWC rider can tell you that the quickest ticket to instability is to suddenly stop the engine.
What’s the big deal about getting “set”? Both instructors agree on this.
“When you chop the throttle, where does all that gas in your tank go?” Martin asked his students. By the law of physics, it rushes forward, helping to settle your bow in the water, ready for a secure turn.
Think of it like driving a rear-wheel-drive vehicle through a curvy course. Decelerate as you approach the turn, loading the front tires (the bow) to prevent understeer. Then accelerate as you come through it to push the back axle into the turn (the aft sections of the hull) and focus the energy equally on the front wheels (the bow), enhancing stability.