SEAMANSHIP

Planing at slow speed requires a deft touch.

My buddies and I often clear the inlet well before daylight en route to offshore tuna grounds. On nights as black as the coffee in my thermal cup, where you can’t tell the water from the sky, we keep the speed in check.

We call it a slow plane— enough velocity to lift my 22-foot center-console for good fuel economy, but at a pace that helps ensure safe navigation in the inky darkness.

A slow plane also can be advantageous in rough seas, where you need to reduce speed for comfort and keep the boat together. You also want the boat to stay on plane to maximize miles per gallon, rather than slogging it out and consuming inordinate amounts of fuel.

Along my neck of the coast, rough seas usually kick up in the afternoon. So, on a long tuna trip, I often cruise out and back at a slow plane. My minimum planing speed is usually between 15 and 17 mph.

Yet every boat setup is different, and you’ll need to learn for yourself your boat’s minimum planing speed and how to run it there consistently. Keep in mind, that speed might change throughout the day. It’s not unusual to require more speed to plane in the morning when the boat’s heavily laden with fuel, livewell water and ice, but less speed later when you’ve burned off fuel, dumped the wells and melted the ice.

Here are some tricks to help lower the minimum planning speed of any boat.

POP UP AND BACK OFF

Rather than easing the throttle forward, punch the throttle to get the boat on plane. Then ease back to find out at what point the boat wants to fall off plane. Just before it starts to fall, advance the throttle to keep the boat lifted. It takes a deft touch, but once you learn how your boat handles at these speeds, it will become second nature.

DRIVE TRIM If you have outboard or sterndrive power, keeping drives tucked in (to create negative trim) tends to create more stern lift than if you’re trimmed out. This helps compensate the natural tendency of the stern to squat, which hampers the boat’s ability to plane at low speed. Once you have achieved a slow planing speed, try trimming out a bit to see if the boat will accept it, but if it starts to fall off plane, trim back down.

TABS AND INTERCEPTORS

Whether your boat is an inboard, outboard or sterndrive, trim tabs or interceptors can help you lower the minimum planing speed. That’s because both can help create stern lift, which enhances a boat’s ability to plane, as mentioned earlier. If you have trim tabs or interceptors, deploy them fully before you jump on plane. Then once you ease back on the throttle to achieve the lowest possible planing speed, retract the tabs or interceptors to see how little you really need to keep the hull lifted. To learn more about interceptors, see page 40.

PROPELLER CHOICE If a three-blade propeller leaves you struggling to stay on plane at low speed, consider switching to a four-blade version. The extra blade area generates additional lift to help you plane at lower speeds. For professional tips on choosing the right prop, visit boatingmag.com/photos/ choosing-right-prop.

MOVING WEIGHT With smaller boats such as my 22-footer, moving forward items such as fully loaded ice chests can help lower the minimum planing speed. The idea is to get the weight off of the stern so it can more easily lift at low speed.

WORK THE THROTTLE Varying sea conditions can affect boat speed, causing you to either fall off plane or accelerate beyond your minimum planing speed. For example, when running amid long-period groundswells, a boat tends to shed speed as it climbs up the swell, and thus you need to apply extra throttle to keep from falling off plane. Once you crest the swell, the boat tends to race downhill, so you need to back off to maintain your minimum planing speed.