Seamanship in adverse conditions

[Fr. Frank]

This topic came up within a series of PM's from a new member. I thought I'd post it here or your edification.

Sliding down the front face of a wave because of applying too much power, or too much speed is something 80% of boats under 100' will face at sea. We need to learn to handle this event. The answer is reduce power significantly, and to already choose whether you will take the wave a few degrees off the port or starboard quarter. Avoid taking the wave directly astern.

Reducing power enables you to ride on the back of a wave, rather than trying to cope with surfing down the face, and losing control when you put the bow into the back of the wave ahead.

As my grandfather, a retired Navy Commander said, "Never challenge the sea directly. Always quarter into, and quarter away from the sea. If you habitually confront her, eventually she'll overcome you. She's bigger, meaner, and stronger, and unpredictable to boot"

I first navigated and operated a boat from Florida to the Bahamas by myself when I was only 10 years old. It was my grandfather's 45' Rybovich. (He never gave a command during the entire 4 hour trip, but lots of 'em before the trip) I received an age exemption and obtained my OUPV "Six-Pack" Captain's license at the age of 16. My first job upon graduating an oceanographic high school was being immediately hired by the same school to teach seamanship and small boat handling. I upgraded to 100 ton Ocean Operator Master license at age 18. Having gone into full-time ministry at age 27, I never renewed that license after it expired when I was 28.

Here's the deal - From directly astern, when traveling faster than the swell at displacement speeds, or at minumum planing speeds, the wave will want to push the stern right or left each time you run into the back of the wave ahead. The steeper the swell, the greater the sideways thrust. Our trying to keep the wave directly behind us is what causes the uncertainty of direction, resulting in the wave pushing the stern sideways. First thing to do is slow down to the same speed as the swell. Then pick a direction, and countering that push from the wave is much simpler - just steer in the same direction as the stern push, just like countering a slight tail slide in a car. If you don't slow down and quarter the sea, because you can't know which way the wave will push, it can get ahead of you quickly, and may result in a broach, and or even capsizing in big enough seas. For the record, I have witnessed a 24' Rinker broach and capsize in only 3'-4' seas. Caution is required.

The issue isn't a lack of horsepower. The issue is knowing how to handle your particular boat with it's own peculiarities in adverse conditions. Other than having someone teach you boat handling in adverse conditions, only practice enables that ability. So go out and practice when the waves aren't too big, and get a feel for how she handles when the swell pushes the stern sideways when the bow buries in the wave ahead. With small swells (under 2') near the inlet, allow the boat to swing freely and broach under power, to know what it feels like. Repeat this while applying power and steering input to learn to counter it. Summer is the best time to learn, while the waves are smaller.

In a heavy sea, speed isn't the need - rapidly applicable torque IS.

[Old'sCool]

And...trim tabs up to prevent stuffing the nose.

[JohnB]

Fr Frank,
Nice article.
Deep V/Sharpe nosed boats like SeaCrafts can do some funny things in a following sea. The Sceptre models, with more weight forward are even more likely to do what you described than the CC's.

[Fr. Frank]

Fr Frank,
Nice article.
Deep V/Sharpe nosed boats like SeaCrafts can do some funny things in a following sea. The Sceptre models, with more weight forward are even more likely to do what you described than the CC's.

Also true of my beloved Seafari.

[JohnB]

I have a 4 blade prop, and a lot of power, so I can deal with it ok even with the "big top". You just have to pay attention . I have had water over the windshield a couple of times, and once, broke all the way over the top.
One of the nice things about these models is the come right back up like a turtle, vs a CC where you have to drain back out, and fear the "2nd" wave.

[peterb]

I agree that you have to be mindful. However, I would much rather be riding the waves than going into them.

[Blue197320]

what size seas are you refferring to? like 2-4 or more like 4-6? usually anything over 3-5 and i wont go out in my 20cc.

[JohnB]

Wave period has more to do with it than height.
3' on 3 sec, especially if it gets rolling, or standing up in the stream is pretty ugly. 4' on 10 seconds, no big deal.

[Bushwacker]

Amen brother! The wave period indicates distance between wave crests, which is more critical than height. A 10 kt wind out of any northern quadrant can create steep breaking seas in the gulf stream real quick, like 6-8' high and 20-30'apart! By comparison, 20 kts from SE is a piece of cake - maybe 8-10' swells, but much longer period, maybe 100' apart!

[nos3665]

Try diving and coming back up in 10-12ft Steep seas makes the boat ride in just fine. Gotta love North Carolina coast.