How Much Can You Take?

Sloop off Miami

A good boat, properly handled, can be a safe place when the wind kicks up.

How much can your boat (and you) take? 
by Tom Dove

First published 6/9/89 in several Maryland newspapers

“Sunny and hot today with highs in the 90s and a chance of an afternoon or evening thundershower. Winds southerly at 10 to 15 miles per hour with higher gusts in thunderstorms,” the radio repeats almost every day from June through August.

Within that familiar, innocuous report are at least two hidden warnings for all boaters on the Chesapeake: the Bay may get choppy from the southerly wind and a thunderstorm may blast you with winds up to sixty knots.Your preparation for a typical summer day should depend on your boat and your experience, in that order. A boater’s axiom states that the boat can withstand more than you can.

Seaworthiness is not necessarily related to size in boats, but comfort generally is, and a skipper’s mental state is controlled largely by comfort. Let’s look at rough weather techniques according to size and type of boat, remembering that there are overlaps; one 30-footer may have a hull shape that gives it a better ride than another 35-footer, for example. 

*** POWERBOATS UNDER 20 FEET: These popular boats are great fun in smooth water but begin to take spray aboard when the waves are more than about one foot high. In a two-foot chop, they become downright uncomfortable and anything rougher than that calls for slowing down and coming off a plane to slow, displacement speed. Their transoms are often quite low with a cutout for the outboard motor, so they are vulnerable to seas from astern.

In a little powerboat, stay off the open Bay if the wind exceeds about 15 knots. In rough water or thunderstorms, head for the nearest shore and pull up on the beach. If you are caught out, anchor or try to power slowly into the wind and seas. Put on a life jacket and stay with the boat, even if it gets swamped.

*** SMALL CENTERBOARD SAILBOATS: A Small centerboard sailboats, especially self-bailing racers and day sailers, can generally handle rough water better than they can strong winds. Thunderstorms are a serious threat and the sight of black clouds building in the west should send a small-boat sailor to the nearest shore to drop and furl the sails. If you have a Sunfish, Laser or similar vessel and are caught out in the open Bay in survival conditions, put on a life jacket, drop the sails and hold on until the squall passes. 

*** POWERBOATS 20-30 FEET: Boats in this size range can generally make progress through all normal Bay conditions, although the ride may be rough and wet when wave heights exceed two feet. Thunderstorms are a different matter. If the water is less than about 15 feet deep and you cannot reach a safe harbor, drop the anchor and ride out the storm. A good anchor with a length of chain between it and the rope rode can be a life saver.If you are caught out in a squall, slow down and try powering slowly into or away from the waves and wind. Keep your speed down to the minimum necessary for rudder control and avoid getting broadside to the waves. 

*** KEEL SAILBOATS: Slow speed and deep draft work against reaching shelter in keel sailboats but these vessels are generally able to ride out nearly anything the Bay can throw at them. If you cannot reach an anchorage as a thunderstorm approaches, drop and furl all sails and ride it out under bare poles, either broadside to the wind or running before it. Check to be sure you have plenty of sea room to leeward and will not be drivenaground. 

*** LARGE POWERBOATS: While three-foot chop will not bother a 40-footer too badly, thunderstorm winds will whip up conditions that require you to slow down to displacement speeds. If the storm is not too severe, you may be able to power into the waves, but 50 and 60 knot gusts will push the bow until the boat is lying broadside to the waves, an uncomfortable and potentially dangerous position.In severe winds and seas, turn your stern to the wind and run slowly, staying well below planing speed. A deep-draft trawler will handle these conditions easily while a high, boxy cruiser without much hull underwater will be a handful for its skipper.

In any boat, keep your eye to the west and northwest this summer. Storms from other directions rarely reach you (I have been clobbered by a few notable exceptions), but cumulonimbus clouds building in the west on a summer afternoon should be a warning of severe weather within an hour or so. 

— The End –