Article on how to take on waves

[Phil M]

Mastreb has more experience in using his sailboat in following seas with a strong following wind, but I do question this. Our boats are designed as sailboats first, with the added luxury of powerful engines. With a fully reefed main, a small daggerboard down, and both rudders down, our boats would best handle large waves in following seas rather than the motor only. There would be no motor cavitation, hence no momentary loss of control, just a steady power from the reduced sail. The motor would be out of the water completely. The primary concern in this scenario is safety.

[Ixneigh]

Leave the engine down if things are getting crazy. The drag will help the yacht track.
Ix

[mastreb]

Phil, the issue that I've had with the waves out here in the Pacific is their fast rolling speed and height: They're higher than deck height and way faster than hull speed. I frequently cannot see over them, and I'm usually having to keep the throttle speed between 12 and 15 knots in order to keep position inside a wave trough. That's way too fast for boards or sails. Using the motor to keep wave position does much more in my experience to smooth out and therefore make safer large following waves.

I've also been beaten up trying to keep a precise course and speed damn the waves, and learned that lesson.

I think you're right that you'd have an easier time "sailing" the waves if the waves were of a speed and period either shorter than LOA or slower than hull speed, most certainly.

The real lesson here is to have multiple strategies for different situations and to know how and when to use them.

[Phil M]

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I've also been beaten up trying to keep a precise course and speed damn the waves, and learned that lesson.

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The real lesson here is to have multiple strategies for different situations and to know how and when to use them.

What do you recall happened as you attempted to sail under those circumstances? Did the boat continually want to broach?

Much agreed. Multiple strategies are always a good thing to keep in mind, which is the reason for my query.

[yukonbob]

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I've also been beaten up trying to keep a precise course and speed damn the waves, and learned that lesson.

...

The real lesson here is to have multiple strategies for different situations and to know how and when to use them.

What do you recall happened as you attempted to sail under those circumstances? Did the boat continually want to broach?

Much agreed. Multiple strategies are always a good thing to keep in mind, which is the reason for my query.

Thats what I keep experiencing in larger following seas. Short runs it works running the troughs with the outboard, but when you have a hundred miles to the next gas station this does not work in the long run. Sailing in them does present a broaching issue when you connect with the next wave as you surf into it at 12 kts. My solution for this is a drogue. Just enough drag (OB down also helps) to stop you from racing into that next wave.

[mastreb]

Yes, that's it, but even more so than broaching (which to me also involves the wind also rounding you up to be broadside to a following sea and then causing serious rolls) the following waves REALLY grab the rudders of the mac and turn them hard--which causes all kinds of helm keeping shenanigans. Much more so than a spade rudder on a keel boat would be affected. Also the flat stern of the Mac gets pushed around dramatically by following waves if the wave speed is faster than hull speed.

So those three combined forces (pressure on the rudders, pressure on the stern, and broaching due to following winds) make Macs a lot more fight in following winds than my double-ended keelboat was (which could largely ignore them).

Often times the Mac will just get turned from the rear and there's not a thing you can do about it. Fortunately it's not nearly as bad as rolling a keelboat because the Mac does slide around on top of the wave rather than being grabbed by it the way a keelboat is. That's why I recommended boards up, because while I haven't figured out how to keep from being spun by a wave, having boards up makes it a whole lot less problematic.

What I wind up doing is a motor sailing (usually headsail only because I don't want the boom swinging around and this always seems to be downwind anyway) a choreographed dance of "S-curves", broaching as you crest a wave and then steering back to course as you surf down the face. The Genoa flaps and fills as it will, and the whole thing probably looks a lot less controlled than it actually is from a distance.

Almost certainly a drogue would help--I should get one and learn how to use it. It would be impossible to sail without the motor without one I think.

The only time it gets really dicey out here is when its time to come into harbor and you've got to put yourself into a channel entrance that's only 50' wide, which is the case we have down here entering Mission Bay from the open ocean. Oceanside can be tricky as well but its a much larger entrance. You can get big fast rollers going all the way into the entrance that don't calm until you're inside it.

I make a couple of false runs at the harbor entrance to be certain I know exactly where the waves are positioning me and I know what my timings are, and go in when I'm correctly positioned and there's nobody in the way.

The big motors on these boats help a lot in heavy seas, no doubt about it.

[yukonbob]

Yes to everything above Mastreb. Never really gave to much thought to the water grabbing the rudders though, good point. I should mention I also run with no DB but do keep the rudders in the water as I'm usually sailing in theses conditions. I think if it got bad enough with the rudder thing in mind I would contemplate steering with just the OB ?? Not running vs running hmm? Running would give more control but then you end up running the risk of swamping the OB or racing the engine. Wonder if the OB would provide enough bite while creating some extra drag? Leaving friday for a 2 week 400nm cruise around SE AK. I will undoubtedly get an opportunity to try the drogue out as well as the OB idea. We have drug the OB before in following seas, still hit 12kts surfing, so I figure a little more should help the cause. Will be in the Gulf of Alaska by Sunday morning and theres always six foot swell out there on the calm days.