rough weather advice - Page 2

gtflash · 22 August 2009, 10:29

Quote:

Originally Posted by SeaSkills

It's not quite that simple. You can cope with large waves relatively comfortably if the distance between them is great enough and you have a big enough boat. It's when the wavelength shortens and the angle of slope becomes steeper that large waves become more of a problem, and the problem comes to the smaller boats first. Generally speaking, size does matter here

The biggest problem comes from breaking waves. As the wave breaks it releases considerable amounts of energy. As a very simple rule of thumb, if a breaking wave has a height about the same as the beam of your boat it is more than capable of rolling you over. Even big boats get knocked down by breaking waves.

There is a bit of a foolish myth amongst some people that RIBs have such fantastic seakeeping abilities that you can do anything you like. Obviously that is not true - failing to respect the sea always leads to problems in the long run.

There is a lot of good advice on this forum, but the best advice is just not to be there ... especially to keep away from breaking water.

Very true! When I was out in the surf, i was not too concerned, i Slowed to about 10-10 knots to look down and check the plotter for hazards, while heading up weather a breaking wave turned the boat sideways and threw it hard enough i head butted the throttle to almost WOT!! That was my wake up call!!!!

Unlike my situation I think there will be times when pressing on IS the only option, for eg if the nearest safe haven is 2 miles infront V 15miles back the way you came??? and I still not sure i would know what to do to get her through it. My boat is very capable, im a average driver, in general I know my limits, i plan a course and weather, i understand throttle and trim control BUT still not sure how to handle large but short breaking waves

Windfinder showed me that the frequency of the waves were 2to3 seconds appart, with the wind heaping them up!!! PS BEST weather web site ive ever found

cuttlefish · 22 August 2009, 11:34

Have a read through this:

http://www.docksidereports.com/rough...amanship_1.htm

Parts 1, 2, and 3.

Cheers,

rupert.

neilda · 22 August 2009, 12:09

Quote:

Originally Posted by chewy

Very true. I think most RIBs can take more than their owners can though.

As I found out!!

JSP · 22 August 2009, 12:14

Quote:

Originally Posted by neilda

As I found out!!

Yeah but I think you'll be a better helm for it

neilda · 22 August 2009, 12:23

Quote:

Originally Posted by JSP

Yeah but I think you'll be a better helm for it

Certainly more safety conscious.

codprawn · 22 August 2009, 13:58

Have a look at some of these videos - quite instructional and damn good boats as well.

http://www.youtube.com/watch?v=ihzaDoG1JfY

http://www.youtube.com/profile?user=...at&view=videos

cuttlefish · 22 August 2009, 14:05

One of my favourite boats. Cost, used, Cod?

cuttlefish · 22 August 2009, 14:11

Someone has commented on how length of the boat matters, but I was just wondering how important the size of tubes and weight of the boat are in rough water handling. Anyone care to give a bit more info?

chewy · 22 August 2009, 14:24

Think hull shape has quite a bit to do with it too.

m chappelow · 22 August 2009, 15:16

Quote:

Originally Posted by rupert

Someone has commented on how length of the boat matters, but I was just wondering how important the size of tubes and weight of the boat are in rough water handling. Anyone care to give a bit more info?

diamiter of tubes/ sponsons do make a great difference even by just a few inches , and a lot is to do with if you are in broken water /surf /large swells or your taking a greenie over the side . going on the weight side in the extreame if your r.i.b does get totally swamped in big waves the whole stability factor kicks in ,have you a powerfull enough engine to keep moving and hope the water sloshes out over the transom or are the bailers /trunks man enough to cope with the amount of water whilst you can gain some control until the next big wave hits you picks you up and you broach or tip over ,even though it wont sink ribs are fine but full of water and the stability is greatly reduced .

cuttlefish · 22 August 2009, 15:57

What about weight. I have seen some 7/8 mt ribs not much more than 1,000 kgs and others that are more than 2,000.

chewy · 22 August 2009, 16:09

Could be down to the quality of build or the materials used?

Jon.esp · 22 August 2009, 16:17

Quote:

Originally Posted by m chappelow

even the old trick of towing some sort of drouge or a long loop of rope may give you better control in some circumstances .,,,i know one boater that sometimes tows an old traffic cone [ pointy bit first] when it gets rough

This is fairly standard text book stuff for yachts and I supose other small craft in heavy weather but I had never thought of it for a small rib.

Apart from the fellow with his motorway maintenance kit has anybody else tried it?

What length of line did they use and did they attach anything to the end assuming they didn’t have a handy traffic cone to hand?

Did they worry about the line at any stage fowling the prop?

Jon

Jon.esp · 22 August 2009, 16:34

And another

Quote:

Originally Posted by Stoo

I came to own my boat after the police service that had owned it, stuffed it and did an end-over-end roll while doing exactly that. I have spoken to the crew that ran the boat and they tell me that the waves were running about 10 - 12 feet and the tubes were under-inflated and that was all it took.

So should we adjust the inflation depending on prevailing sea state?

Jon

cuttlefish · 22 August 2009, 16:43

Sounds like we should all buy sailboats, but then, there is always the risk of the having the keel fall off - then you are swimming in it....

chewy · 22 August 2009, 16:54

Quote:

Originally Posted by Jon.esp

And another

So should we adjust the inflation depending on prevailing sea state?

Jon

Should be pumped up regardless of the sea state, another case of the Police been eejitts.
The give away was in the name Rigid INFLATABLE boat, not Rigid flat boat.

codprawn · 22 August 2009, 17:38

Quote:

Originally Posted by m chappelow

it wont sink ribs are fine but full of water and the stability is greatly reduced .

That is quite a controversial statement.

Alan Priddy swears a RIB full of water is far more stable. My boat is far better when it has 500L of fuel on board. And a bloke I know was an RNLI helm for many years. He said the roughest conditions he was ever in was when they had to transfer the crew of a lifeboat back to land using a D class - he said is was perfectly stable as there were so many people on board and it was full of water.

cuttlefish · 22 August 2009, 17:56

would seem to prove that the heavy the rib, the better.

JSP · 22 August 2009, 18:10

As I said before, I was more comfortable staying at displacement speeds. I think the ride was made better by having the flooding hull open on my searider. Just wish I could bloke and unblock it on the move.

codprawn · 22 August 2009, 18:13

Quote:

Originally Posted by rupert

Have a read through this:

http://www.docksidereports.com/rough...amanship_1.htm

Parts 1, 2, and 3.

Cheers,

rupert.

Good reading!!!