Boat handling in following seas

Two keys I believe and they are speed and control of direction. Finding the best speed is difficult at first, but you learn the wave timing in respect to your boat and it becomes far more instinctive. We were made to practice surfing. Now, we do have one advantage many here don't and that is we have extra power in reserve.

The other thing is steering. I heard, was even taught in one classroom, to take it off autopilot and take over. However, in hands on training, we were shown how to adjust the autopilot to the right sensitivity and use it. It can then keep direction better than you or at least easier. You keep your hands ready however to take over.

The first time I ever had an issue with following seas I was out with a sail boater. I was keeping pretty busy at the helm, and the boat was moving around a quite a bit. My sailboat buddy spoke up after a couple hours saying " man, try slowing this thing down ". Pulling back on the throttle life instantly became better, and the difference in the ride was amazing.

That was a good video, and very informative for me. The more experience I get, and the more I read and listen to what others have to say, the better I feel about handling the boat. Phrases like " detach from the weather".... " move faster or slower than the water".... now mean more to me since I've been in a couple of situations.

Conall

cardude01 said:

Holy crap! So in this case instead of trying to outrun the swells could you have slowed down? Like they mention in the video?

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Most of the time we did not need to slow down because the waves outran us. When I bought that boat, it was a 15kt cruise boat, and 22kt WOT. Several times we intentionaly slowed like the video showed and that worked. 4 times it did not work.

I've spent a lot of time at sea in ships and commercial boats. You can reach a point where it's safer to turn around and slowly go into the waves. You don't want to get to the point where you're barely avoiding broaching. If you can, stay in deep water, 100 fathoms or more. Ocean swells grow steeper and closer together as they near land and shallow water.
I have been in a following sea where I was making turns for 7 knots yet made 22 knots in the PNW.

Lepke said:

I've spent a lot of time at sea in ships and commercial boats. You can reach a point where it's safer to turn around and slowly go into the waves. You don't want to get to the point where you're barely avoiding broaching. If you can, stay in deep water, 100 fathoms or more. Ocean swells grow steeper and closer together as they near land and shallow water.
I have been in a following sea where I was making turns for 7 knots yet made 22 knots in the PNW.

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That's part of looking at fuel needs for transatlantic and transpacific crossings. One needs to have enough fuel to go 24 hours with no progress or slowly in the opposite direction.

Looking at the back end of the GFC Sea Ray, I am reminded of an often forgotten element. Trim tabs. They can be your friend or enemy in following seas. No two situations are alike so be aware of tab position and play with them if needed.

psneeld said:

You can also back in an inlet if it looks too hairy.


On many a surf salvage job I had to back through several lines of breakers to get near a stricken boat and keep the bow and power where I wanted it.

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That's interesting,
Never even thought of that but would be very slow going.

A big rudder that can be moved fast and the ability to anticipate when to swing it over at the right time before the stern moves sideways much solves most stern sea problems IMO.

Not in a breaking inlet.... a slow boat with a big rudder is the worst unless you have a double ended or canoe like stern.


Most breaking inlets are not bad for the whole trip...usually sand waves create the breakers and vary enough so there are dead spots where maneuvering is possible.


You can also back when the waves aren't pushing too hard to shorten the tough spots.

Hawgwash said:

Looking at the back end of the GFC Sea Ray, I am reminded of an often forgotten element. Trim tabs. They can be your friend or enemy in following seas. No two situations are alike so be aware of tab position and play with them if needed.

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On the boats I have run, the tabs would be taken off to sink the stern for better directional stability. I want the bow forefoot out of the water to cut down on shearing off. In all but absolutely flat conditions I order the ext cabin doors and hatches closed, tabs up, life vests on and everyone inside. I don't want to be worried about someone running around on deck.

Call me overly cautious, but once a passenger went below. It was stuffy, and opened a hatch as we took green water over the bow. That was a complete mess.w

The photos of that boat in trouble are striking, but this one image really shows something rarely seen, but spoken of, as another reason it is called a "Fly Bridge" or "flying bridge."

Look closely and one can see the helmsman is literally flying off the bridge as the boat rolled. Yes, that is his body, head down. Wow!

I spent 3 days hand steering with two crew sailing south out of Cape Flattery in seas that averaged at least 25ft+ and many were quite higher. All breaking. My cockpit (see photo) was at least 4 ft off the water and was constantly filled with foaming water. The entire trip. But I ran at 8.25 knots, left-right-left-right off course line and overall she kept track quite well. So some thoughts:

1) I would never consider dragging a heavy rope to slow, not even floating poly. The line would definitely at some point get tossed under the boat and tangle the props.

2) I think a drogue might work well as long as it kept high tension on the line.

3) Certainly running with the seas is preferred to head-in, but I have not sailed in life-threatening or hurricane conditions. Perhaps others can comment on those.

4) I've always considered the word "poop" to mean a more catastrophic occurrence, something that might lead to severe damage, so I'm not sure that you all would consider the cockpit filling with water as being pooped.

PS- No more cockpits for me on boats designed for ocean work! Coastal cruising, floating condos, dives boats, etc., are great, but out in the big waters - no way. Of course, there are plenty of Norhavns crossing oceans out there, so perhaps I'm wrong?

makobuilders said:

I spent 3 days hand steering with two crew sailing south out of Cape Flattery in seas that averaged at least 25ft+ and many were quite higher. All breaking. My cockpit (see photo) was at least 4 ft off the water and was constantly filled with foaming water. The entire trip. But I ran at 8.25 knots, left-right-left-right off course line and overall she kept track quite well. - No more cockpits for me on boats designed for ocean work! Coastal cruising, floating condos, dives boats, etc., are great, but out in the big waters - no way. Of course, there are plenty of Norhavns crossing oceans out there, so perhaps I'm wrong?

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That's why Nordys are built in the main with cockpits we coastal folk think are too small - for precisely the reasons you raise above. I loved the Nordy55, but the cockpit, compared to the rest of the boat's proportions, was for me, too short, but they are designed door ocean crossings. The Nordy 60, like Twistedtree's, is the 55 with extras cockpit, essentially, though no doubt there some other changes. The cockpit was the main beneficiary from the extra length. I'd be interested to hear Twistedtree's opinion as to how he would feel re an ocean crossing in the 60.

ocean breaking waves and breakers on the shore /shallows are 2 different animals. size and breaking aren"t the parameters for danger as much as steepness or curling.


even waves breaking in inlets can be 2 very different shapes.


at the point where waves build quickly enough to curl is where even little ones will cause a broach or pitchpole.


the two types of waves are being discussed back and forth here and dealing with either can be similar or very different based on how big and unavoidable those curling waves are.


once in curling waves, you are borderline good seamanship to survival in a matter of seconds.


pooped is just water over the stern....can but doesn't have to be catastrophic.

Mako

Judging by the small scuppers in the picture shown, a boarding wave into the cockpit would indeed prove interesting. How did you find yourself in those conditions given the forecasts available in this era?

I didn't describe my particular example situation as "survival" (because I lived!) but honestly I was scared sh*tless. It was a bad early May. The Strait of Juan de Fuca was wonderful, rounding the Cape and turning left was no issue and I headed about 34 miles offshore to keep lots of sea room. A day later is when it took the turn for the worse. The seas took constant helmsmanship and if I had turned an extra 10-20 degrees then the boat would have broached. 100% no doubt about it.

I kept in contact, checking in, with Coast Guard as I cruised south down the coast. CG kept warning me about trying to cross the various bars to seek shelter, but I couldn't change course anyway since we would have rolled.

Sunchaser, the scuppers were a joke and the teak flooring and the lazarette hatch leaked somewhat. Thank God for the watertight bulkhead and the little electric bilge pump. When I was in the wave's troughs the foaming water always flooded the cockpit as it did with the breaking waves when at the crest. Anyway, there was nothing to be done about it. There was a big picture window looking into the cockpit from the aft stateroom, and before I left I had replaced it with laminated glass. It was like looking into a fishtank from down below.

The funny thing is that the one thing that scared me the most was the thought of getting seasick, since my two crew were not the most experienced sailors. Luckily, to date I have never been seasick in my life.

You PNW boys have got some truly crazy cruising grounds out there! My hats off to you for sailing up and down the coast and living to tell about it.

Regarding forecasts, I honestly don't remember, but I certainly wouldn't have headed out if they were calling for 2 to 3 story seas. I recall crossing an oil tanker who called out to "that little boat rolling in the seas off my starboard" and being asked what the hell I was doing out there. My boat was 65ft and I thought I was a big boy when I bought her!

Nature (and giant tankers) can be quite humbling

PS - I framed some photos I took but they are all in storage back in America. Wish I had scanned some. Makes for great conversations during cocktail parties, haha.

I don't know the exact circumstances. Certainly heading 34 nm off shore took you several hours further from shelter. Were you continuing to monitor forecasts as you traveled? I just can't imagine a forecast that far wrong one day ahead and in following the CG stations at all the bars, we regularly found warnings well in advance of closures. The most we saw in our time there was 15' but it was 10' at 14 seconds when we departed and 15' was just an occasional swell and wind wave combined, definitely not the same as 15' wind waves. I'm just thinking that Cape Flattery to Grays Harbor is only 12-13 hours at 8.25 knots, Astoria only another 5-6 hours from there. Maybe we were lucky and we did have more speed, but we never felt uncomfortable and never found the forecasts three days out to be significantly off and certainly not for the next day. Further south the inlets are generally tighter and close sooner, but if one is a closer distance from the coast, there are many inlets along the way to get in before the worse conditions hit. When did the forecast first change to the worse conditions.

Just trying to understand and you skip over any forecast or change in forecasts to suddenly in the 25' conditions.

Something else not mentioned (I think) is boat trim. It's my opinion that a boat floating on her lines is about as good as it gets. It's also my opinion that if a boat is not going to be in trim being heavier aft is much preferable to being bow heavy.

I've seen many trawlers (pics mostly) here on TF considerably bow down. Since the pointy end does'nt float as much weight as the square stern being bow down is probably much more common. Also it appears many twin engine trawlers have the engines too far fwd so as to optimize interior layout.

Personally I try to keep Willy a bit stern heavy. I did'nt "learn" any of this and consider it more or less a gut instinct. I'll read opinions and facts with interest.

Eric, check post #39. I run planing hulls, but my thinking is along with yours. Also a V hull on a planing hull is best for a following sea. Both my Sabre and Blackfin track like on rails. Hardly any wheel work unless coming into a bad inlet. I think Bertram proved that with their Ray Hunt designed hull.

Anyone seen a transcript of this Youtube video. I would like something to keep reviewing until I have it down so that when I need it I will remember the equations.

In the alternative an article covering what to do in following seas.

Strange how the weather doesn't cooperate in requiring special actions only when I am ready for it.

Here on west coast USA, the prevailing winds are on-shore. Worse wave conditions are when there is an ebb tide in the opposite direction of the wind. Attempting to going stern-first seems like a fool's errand as the tide will push you out to sea.

psneeld said:

You can also back in an inlet if it looks too hairy.


On many a surf salvage job I had to back through several lines of breakers to get near a stricken boat and keep the bow and power where I wanted it.

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That's called experience and knowing how to handle things!

In such conditions, do you tow your dinghy? Last Wednesday we crossed the Straight of Georgia in what started out with 5-15 knot wind and the usual choppy but navigable quartering seas but which changed to much bigger following seas with 6-8 ft breaking waves by the time we were half way across. On two occasions I was sure we'd broach as a big swell caught the stern while the bow was being slowed by the prior wave's back side. Wife was looking down into green water from inside the salon while I was navigating from the flybridge. Pucker factor indeed! To the point of the video, slowing down to 5 or so kt did make quite a difference when I finally had the sense to do so. However I ask about the dinghy location because ours was on transom davits and I wondered during that sobering crossing whether towing it would have been a wiser choice. How much opportunity would I have to detach the dinghy with the boat broached? Could I even hit the button on the VHF in time?

Towing might have helped or hurt, Too many variables, but doesn't matter because you had no way to plan for it, but shows you have to live with either once the weather turns bad.


If you were in open deep water, 6-8 foot waves probably were not going to broach you unless your vessel has been severely modified or poorly loaded. Don't know what vessel you have, but really haven't seen any cruisers that cant easily survive 6-8s....no matter how uncomfortable. Surf, shore break, curling inlet waves are all another story.


Scary yes, but probably not a full knockdown and sinking.


If that worried about a broach...one of the few emergencies you get no time to do much abandon ship execution, the ditch bag should be at your side and a call should be made to someone stating your concerns and a 15-30 minute watch schedule made up till you reach better water.

Jimbalaya

I have a sister ship to yours. We slow way down in big seas, 4-5 knots.

Use your throttle to give a burst of power to push water past the prop. You are not trying to gain speed but a fast blip of power will get that rudder working if you have it cranked all the way and the hull is still not responding.

You have a good size rudder but if the boat speed is too close to the wave speed there will be little steerage.

The bow is a little fine and will dig if the following wave pushes you ahead. The slowing will help keep those waves rolling under you instead of pushing you so much.

Still will be lots of wheel work and and holy shimblefinnies but the boat will keep going.

May the next trip be a little kinder.

Commercial fishing I once made 22 knots in a following sea while making turns for 7 knots. The boat had twins and large rudders, so control wasn't an issue. It was night and couldn't really see swell height but guess near 50'. Off Oregon/N. Cal. In heavy seas, you go with it until you have control problems and then the only choice is to turn and head into the swells. And stay offshore and out of any ground swell. That only makes them steeper and closer together.
In a warship, near a typhoon, we had to turn around and might not have made the turn except for twin screws and 85,000 hp.

I didn't answer part of your question about the dinghy.
We too carry the dinghy on the swimgrid on Weaver davits. No, we do not tow it in rough conditions. Ours is a hardshell Livingston but maybe a rubber dinghy would be better in those conditions.

If you did tow you would need to tow it either tight up to the swimgrid or a long ways back or the dinghy could be slammed into the main boat. If it filled with water it could be a big problem although maybe act as a drogue but still not good and you would lose its usefullness anyways. If you did tow I think I would attach a short length of chain to provide some drag to keep the dinghy back.

We don't have the heavy seas compared to those in Northern California but there are two spots in Southern California that can get pretty heavy. Mission Bay San Diego, and Oceanside on a big north in the winter. I have seen 10 to 15 foot waves to the entrances of both including complete close out sets across the bar of Mission Bay. I was not in a boat, but watched some experienced fisherman run it on some bigger days.

In addition to the large rudder, Tortuga also has a substantial steel keel. CLectric, I would guess your boat has the same? If so do you find it helps or hurts handling in following seas (or strong currents)? We definitely feel the effects of currents, but I don't have enough experience with other designs to know if this is the nature of semi-displacement hulls or particular to our boat. I think I read Steve Dashiel's thinking was to have no keel to allow the boat to slide down a wave and avoid the keel digging in.

I had a 26' Dory style commercial fishing boat in Newport Oregon. One windless day we had steep building waves approaching the jetties. I had blown my exhaust hose so I was limping in going only 5 knots. The steep 25' waves never broke and kept passing under me going faster than I was. At the dock my friends 35' boat was sitting with the poles and gear ripped to shreds. He had surfed down the face of one wave and was shoved into the next. Lucky to not have sunk the boat.
My slow speed, letting the waves pass me, saved me from surfing down the face of the waves. It was the mechanical problem that saved me.