Dealing with rough seas (large wave's)

Re: Dealing with rough seas (large wave\'s)

I tend set the throttles for a speed compatible with the wave pattern and then try to leave them alone. Agree flying off the top of a crest especially at high speed and landing on the middle of the next crest in a head sea is not good for fillings and could split GRP hulls, that's why the GRP thickness on pilot boats is up to five times thicker than leisure boats and reinforced with stringers. US trawler yachts like Nordhavn have indestructable GRP hulls as they are expected to deal with lots of weather.
 
Re: Dealing with rough seas (large wave\'s)

Well for the first time ever, I find myself in disagrement. The art of getting any boat through the rough stuff, is damage limitation. Theres nothing gung ho about it. Last time I met Brendan, was in Salcolmbe 5/6 years ago. He'd ripped his window screen off. Not a big deal as it happened, but another wave or two???

Yep I started with 8ft and worked up.

If you boat long enough, you will discover, that boats even with two engines can both stop for very different reasons, even though well maintained.

Three or even four bilge pumps can easily become, unuseable. For all sorts of reasons. (they are not the most reliable things).

In the bad stuff, I find that about eight knots, keeps a good bite in the water and the boat in control. It's fairly comfortable and the auto pilot can cope. Just send the boat out to sea, away from the termoils of close to land. Soon things will settle down and there will be an understandable direction to the sea.. Mostly, the sea will be now on your beem or behind you. Less heading into a F8 or more, of course. Once sea becomes aft of the beem. Easy peasy, full wollop in a good boat.
 
Re: Dealing with rough seas (large wave\'s)

Hi Mke play with the throttles well,........ you mention setting your throttles and thus your speed to suit conditions indeed more or less what hlb says hes sets it about 8 knots in head seas with the autopilot on.

At 8-10 knts that makes a lot of sense and it would have to be pretty big waves in head sea to create slamming.

However if you want to keep just on the plane say 13-14 knts then you can do so by reading the incomming waves easing the throttle at the top of the crest to prevent slamming into the trough then opening then a bit to keep your nose from digging into the trough and so on. I personnally prefer to helm in big head seas, I rarely use the autopilot, after all it cants see that extra big sucker which comes along every now and then.

If the bearing to your destination means the seas are on your nose, I adopt the above but then every now and then turn and accelerate along a trough or indeed get it behind me for a while, this gives a break from the endless water dousing and boat bucking up and down.
 
Re: Dealing with rough seas (large wave\'s)

Good interesting theory, I would not deliberately set out in rough conditions, but have, of course, been caught out!
Some practical own boat tuition would be good, if I could keep my nerve and actually leave the harbour /forums/images/graemlins/grin.gif
 
Re: Dealing with rough seas (large wave\'s)

[ QUOTE ]
Once sea becomes aft of the beem. Easy peasy, full wollop in a good boat.

[/ QUOTE ]

In a planing boat - yes /forums/images/graemlins/smile.gif
 
Re: Dealing with rough seas (large wave\'s)

You can't "play the throttles" for hours on end. In fact, it ain't easy on a big crusing boat to have much effect on a second-by second basis by pratting about with throttles. It not like a car.

In rough weather when actually out at sea like at least midchannel, you can often find yerself with biggish 3+ metre sea, and if its ahead of the beam, bit of a bummer cos yer can't plane into it without smashing the boat up.

So frinstance say coming back Cherbourg to Pool in a NW 6-7. Now, point it straight at poole and urg, it'll be like with #1moose in biscay and he got it going as fast as he can with no smashity noises - 9 knots, which means bluddy hours it this splosh.

So, i had a go, and pointed it in another direction, like NE in this case, and get it going at 20-25knots, and steer by *Hand* not autopilot.

Now, you can actualy nip (to the left) over each wave, dropping back to NE now and again, but pinching to the left as much as poss, choosing a route on wave backs.

Soon enuf of course, cos you are going fast, you will have closed the coast, and hence sea state much better soonish. So the trick is to drive fast, but not in straight lines all the time.
 
Re: Dealing with rough seas (large wave\'s)

I agree with tcm
Not convinced that the autopilot is much good in a big sea.
On the passage when the above pic was taken the auto pilot definately didnt cope. So after that I spent a bit of time resetting it up - not sure it might now cope.
However, if you take the helm yourself, you can anticipate the next wave pattern better than the auto pilot cos you can see the auto pilot cant.
I'm sure it helps to have the rudders pointing in a better position before the wave hits.
And I'm not one of these people who drives much - I always use the autopiolt if I can.
 
Re: Dealing with rough seas (large wave\'s)

Well I suppose it depends on a thousand reasons, my AP copes with most anything. So option one, is to just leave it to it and bumble along, but not necesarily straight into the waves. Option two is steer like a maniac, get two waves right, then get stuffed on the third one.

As TCM says, the wiggling throttles about on anything other than a skate board, just dont work.

But in any case, all seas are different, so theres no hard and fast rule. I've seen enourmous seas, that you can just zoom over and little ones that are a pain in the bum.
 
Re: Dealing with rough seas (large wave\'s)

agree AP gets to a point of being useless - but also verging on dangerous.

I have Raymarine ST7001+ gyro and all the gubbins.

the Raymarine kit allows sensitivity to be dialled up or down.....moving up to "+7" in heavy seas help.

thing is once the AP cannot cope you start drifting way off course and eventually course alarms sound...dangerous if you place the same faith in the AP as calm weather !!!

you need to be paying quite close attention to your COG to see when the AP has a benny, disengage and manually correct I find it easier to just steer manually and have confidence in my own abilities to keep us in line.

either way....tiring but good fun!
 
Re: Dealing with rough seas (large wave\'s)

what I personally do in big seas 2 metres plus (Force 5) of wave height
is start with a minimum planning speed then if I see it handling it good I usually start trying to find the limit of the speed I can cope with, without slamming or minimum slamming

I thinking knowing your minimum planing speed for any planning boat is one of the most important factors for a comfortable trip
the lower the minimum planning the better advantage especially for not so big boats - 40 feet but I personally think this equation works for all sizes

I personally dont agree with the throttle play solution, the theory is good but only if you want to speed up your trip or want to have fun
plus this usually equates to more fuel consumption and a lot of stress on the engines IMO
 
Re: Dealing with rough seas (large wave\'s)

[ QUOTE ]
I think you know I already know that, without being taught! /forums/images/graemlins/grin.gifI'd love to teach rough weather handling, but difficult to set up the conditions.

[/ QUOTE ]

As was by no means implying that you didn't but just be good fun to go out and find some really nice wind over tide F6/7/8 + stuff in the rib and really play. But not for the inexperienced so you'd better come with me /forums/images/graemlins/laugh.gif

As to setting up conditions the Chi bar can be interesting as can the over-falls off the Needles - but yes, it can be tricky planning too far ahead.
 
Re: Dealing with rough seas (large wave\'s)

More than theory actual practical experience old chap. I too would not deliberately set out in rough conditions
 
Re: Dealing with rough seas (large wave\'s)

[ QUOTE ]
Well for the first time ever, I find myself in disagrement. The art of getting any boat through the rough stuff, is damage limitation. Theres nothing gung ho about it.

[/ QUOTE ]

I agree with you. It is damage limitation and it's also about being on the right boat. I don't go thrashing around in big cruisers using the same techniques I do in a rib, and even then there are ribs and ribs. Some ribs I've driven I wouldn't want to use in a bath, others I'd take to the ends of the earth!

I recall one trip in a 30 foot rib with a single big diesel on a jet drive where we were climbing 20 foot waves in March in F7 on the nose. What a thrill that was, but the boat was a big heavy Ocean Dynamics built for the conditions. My, what a time we all had there - soaked to the skin and laughing like kids while hanging onto robes rigged along the side. Power on power off every few seconds and hearing that big 330 lump behind us taking everything in it's stride was very reassuring. We did however resist the temptation to round Land's End when the wind got to F10 and it was dark! Slept on board in St Ives harbour with waves breaking over the sea wall.

A planing hull needs a different approach to a displacement or semi displacement - ask Benjenbav about the difference he noticed on our trip back from Fowey last week about how he thought his planing hull would have reacted in some of the seas we had.

The little 5.4 meter I was teaching on the other week was a great little boat - a Ribcraft - and again given the limitations of size I would not do with it what I would do say with Ribcraft's big 9 meter sea safari version with twin O/Bs. I also know of another make - an own design - that will happily thrash along in big seas at speeds that would make most people's eyes water - a really stunning hull with a 300hp Yamaha on the back.

One of our instructors is also a rough water handler RNLI and he puts boats through paces that even I wouldn't want to really go experimenting with.

While it may sound gung ho, remember that I'm talking personal here and not with my instructor hat on. Surfing on the back of waves and climbing up the back of others is great fun in the right boat and I can't stress this enough. It also has to take into account the experience of the crew - this is of paramount importance. Having Brendan on board would mean whahoo time. Having the family and less experienced folks on board would be "driving miss Daisy".

While there are some basic rules to rough water handling, you can't apply them all the time - each wave is different every situation is different and just applying the rules does not always work. You have to fully understand them to break them at the appropriate time. Simply sticking the auto pilot on does not solve the problem, in really rough seas the thing would be useless - it can not "see" wave direction and then it's simply down to Mark 1 Eyeball

Comments have been made about playing with the throttles. Again good in some situations but not so good in others and the type of boat will again play a part. You can't generalise.

People should get hold of a copy of Dag Pike's book "Rough Water Handling" a great read and some really good tips.
 
Re: Dealing with rough seas (large wave\'s)

[ QUOTE ]
agree AP gets to a point of being useless - but also verging on dangerous

[/ QUOTE ]

That depends which way the waves are coming from. Agreed that in big following or quartering seas from astern, the autopilot might not react quickly enough to stop a broach but that depends on the boat as well. Some boats are better following sea boats than others. In head seas though, I've always found that autopilots work fine. Personally I would'nt have the patience to play the throttles and steering for a long passage into big head seas so for me, it's a case of finding a comfortable speed at which the boat and crew are not shaking themselves to pieces
 
Re: Dealing with rough seas (large wave\'s)

Trouble is Mike, posting on here is like giving some one a stick to beat you. They either take everything you say, to the enth degree, else only read half.

Then, they take the assumption, that your bombing along on AP, in a F10 down a 20 yards wide channel.

Where as of course, in reality, if the AP kept packing in, you would soon stop using it and mostly, a mile or two off course, makes no difference anyway.
 
Re: Dealing with rough seas (large wave\'s)

Sensible as usual, hlb
 
Re: Dealing with rough seas (large wave\'s)

fairy snuff.

like a lot of times in this boating lark it is about applying a bit of noggin, using the tools you have (AP, throttles, outdrive trim, tabs, steering) and seeing what is right for the circumstances at that moment.

on my Sunseeker I can use the throttles to lft the nose a few degrees to sto me stuffing into the back of a wave...because I have 630hp of duoprop on a 37 foot sportsboat...totally ineffective on my 46 foot flybrige cruiser.

likewise AP is fine but I know it's limitations and where I wouldn't trust it to not go pete tong

it's always different - which is part of the fun!
 
Re: Dealing with rough seas (large wave\'s)

One aspect not mentioned in handling rough seas is, ensure you dont encounter them.
OK, there are some very experienced boaters on here who have the experience to cope, but as it was some one new starting out, my limited advice would be build up some experience starting with fairly good conditions, maybe avoiding headlands, checking tidal streams and forecast to ensure you ll be boating in manageable conditions gradually building your confidence and ability.
What you dont want ever to do is find yourself in conditions that you, the crew or the boat cant handle. Safer and more comfortable still to be tied to the pontoon.
So, I d concentrate on learning the smaller waves, and gradually work up. That will give you plenty to do!
Or go out with David /forums/images/graemlins/tongue.gif
 
Re: Dealing with rough seas (large wave\'s)

"Trouble is Mike, posting on here is like giving some one a stick to beat you"

_______________________________________________________________

No one is beating him and I dont think they have made assumptions? they are giving their opinons which may be contrary to Mikes, as indeed I did, as I prefer not to use the autopilot for reasons I mentioned.

This is a forum the point of which is to share views. The only one who used to beat people was of course the much missed GCI cos he could not take anyone having contrary views to his.
 
Re: Dealing with rough seas (large wave\'s)

Without wishing to sit on the fence, i've found its sometimes best to use the auto pilot, other times best to try and steer round the peaks a bit. I think it may be down to different types of sea and the angle you're trying to take the waves at. For instance a wind against tide sea will generally have steeper faces to the waves and therefore slams more, so i've found it helps to steer by hand. On the other hand, when we had our heavy channel crossing in a NE F6/7, I found it better to stick the autopilot on and plod along at 8 knots, and after sh1tting ourselves for the first twenty minutes we actually settled into a routine of up one wave, down the next, and it all seemed a lot less scary.
 
You must log in or register to reply here.

Other threads that may be of interest

mogmog2
Maxwell windlass 10 VW looks interesting (to a windlass noob)
2 3
Replies
59
Views
1K
mogmog2
mogmog2
bluey01
Anyone want to design a folding sailing dinghy with me?
2 3 4
Replies
66
Views
2K
bluey01
bluey01

Share this page

Top