Rogue Wave

[S&S]

I'd steer a little to starboard where it isn't so steep.

[Cheechako]

I'm not sure what the true definition is of a rogue wave, but unusually large waves DO occur. They are recorded by the wave height recording bouy off the Northern end of Vancouver Island every winter. Waves in excess of 100 feet are recorded pretty much every winter up there...

[feelsgood]

Hi I once sailed a westerly sirrus 23ft on a circumnav and only incountered a couple of waves that realy mae my eyes open and on both occasions I ran and let it pass me. The reason was that i only had sails and no motor so to head into it would have been desaster. I always stream a big warp with a bight in it in rough seas and am still here after 57 years at sea and most of them spent in small boats. The size is not importnat it is how the boat is prepaired for the passage that counts

[barnakiel]

The 100ft waves - link?

I read about waves in excess of 100ft caused by hurricanes (single ones and not confirmed).

But the ... Vancouver Island ... every winter ... failed to find the source info. PLS write up.

One more piece - "... the South African coast where the eastern current came north and the western moved south causing turbulance where they met..." - it is SW current vs. SW gales, no turbulence, but bad wind-against-current, yes please very much so. ;-)) Been there - yes dangerous but can be done - much of a challenge for anybody going non-stop. And the sharks - yes they are there, but believe me they will not be your main preoccup if you do get that bad wave.

Facts, numbers, please!
b.

[Cheechako]

I'll see if I can find anything. If I remember right it was in that large format fishing trade magazine.. National Fisherman? Pacific Fisherman? There's a lot of fetch from Korea to Canada... gales all winter long..... large Crab boats lost up there every year....

[Cheechako]

I'm still looking, there is a lot of interesting data though! It looks like normally they lump anything over 8 meters together. At the Bowie ocean bouy over 8 meters appear to occur between 2 and 3% of the time (yearly) the period between waves looks to be an average of maybe 11 seconds. I havent found any data on highest recorded wave etc... I guess that would mean that the wave height is over 8 meters 1000's of times per year ..? Here's one site...Swell Map, Wave and Weather Maps for Canada - surf-forecast.com

[Bash]

A rogue wave, by definition, is singular. It's a completely random phenomenon. Your chances of being hove-to if one happens along are negligible. You're not going to get much warning of a rogue wave, especially if you encounter it at night.

Heaving to is a great storm tactic, but it's not going to work well once the waves are higher than your spreaders regardless of what sort of keel you have. I hove to once in 15-foot seas to reef, and it worked remarkably well. But I don't see how a boat would manage to keep a hove-to trim in 40-foot seas without some sort of drogue system.

That said, I must confess that I've never sailed sustained seas higher than 18 feet, nor do I ever want to. That was the point, for me, where I really didn't want to go forward of the cockpit.

[Cheechako]

yea... roger... on the rogue def..
I hove-to off of Hatteras one night and frankly it felt more like lying ahull! If the seas are steep enough, heaving to with a modern long fin skeg underbody just doesnt work. I tried every thing and every combination I could think of. The boat would almost settle down making a little way to track and then the seas would shove the bow down, stopping the boat and "lying ahull". It would take minutes for a lull in the waves for the boat to strat moving again and BAM! I just went inside and closed 'er up. Every port and hatch leaked as the waves broke over the 47 ft boat. After a few hours "rest" (?) I just headed down wind (should have done that the whole time!) I think the problem was the short wave period... probably due to the Gulf Stream. I hove-to in the Pacific in my little 30 footer (modified full keel) and it worked good. Long wave periods though!

[phiggins]

On my last trip to the Caribbean in 2005/6 we got knocked down twice. The first time was by a water spout that snook up behind us.

The second time was crossing from Cuba to Florida in the middle of the night. We had about 8 foot waves some breaking on our beam. My buddy and I were both sitting in the cockpit, him at the back on the port side myself under the dodger on the starboard side. Both of us had safety lines attached thankfully. I was sitting there half asleep looking back at my buddy when suddenly he disappeared in wall of water going through the cockpit. The boat went completely over on its side but recovered quickly. I don't know how big the wave was.

We now have a procedure for dealing with such waves if we see one coming: We both face the wave, bend over and put our heads between our legs.... and kiss our ass goodbye.

[estarzinger]

Originally Posted by Cheechako

I'm not sure what the true definition is of a rogue wave, but unusually large waves DO occur. ...

The official definition is statistical. Rogue wave = 3 sigma wave. Another less official definition is any wave more than twice the significant wave height. Some wave definition here: http://www.mxak.org/weather/waves.pdf

But it's the wave shape that is more dangerous than the height. A nice long wave length 100' high wave would present no danger while a breaking 30' wave can be a serious problem. And unfortunately there is no real science/measurement/reporting on wave shape.

Some wave articles I have collected are here:

http://www.bethandevans.com/pdf/bigwaves.pdf

This is also interesting: http://www.jordanseriesdrogue.com/D_9.htm

[osirissail]

Several decades ago a 104 foot high wave went over Sable Island off Nova Scotia as recorded by the automatic weather station on the flat island. Before that, rogue waves were myth and legend to land lubbers. After that they were believers. But as others have said, there is really no time for preparation, you just have ride it as best you can depending upon the wind so you can either climb the wave or surf the downside. I would prefer to climb the wave to be able to slow the boat and let the wave pass underneath. They are reportedly very fast moving. Being prepared before setting to sea with everything battened down and keep hatches and portholes closed underway with washboards in place greatly reduces the chance of water entering the boat in the event of a roll-over. I re-built my sailboat such that I could in my mind grab the keel of the boat turn it upside down and shake it - and nothing big would come loose inside. That means good engine mounts that are shaped to also "suspend" the engine if inverted. I have straps over things like the water heater and sturdy bolting of everything else. All floor boards have positive locking latches and all lockers have latches and top and bottom twisting retainers. Generally most any boat that does not take in water during a roll-over will survive the experience. It is the people in the boat that need protection from flying objects and in cockpit systems to keep the people attached to the boat when she rolls.

[George Wade]

Originally Posted by estarzinger

Do you pray - might be the time to start

Doesn't anybody have an instant helium dirigible in the aftermost locker ? You could fly with the keel and rudder left in the sea for steering and direction. It would be a new kind of sailing vessel.

[forsailbyowner]

On small boats, aren't they much stronger structurally just because they are smaller and have shorter distances between bulkheads, framing members and less distance between spans. In most production boats I haven't seen big differences in the thickness of the layups between boats in the 30' range and 50' range. The triton being heavily built to start with would to me be more capable of supporting tons of water crashing on top than many much larger boats without structural failure. What am I missing?it would seem to me the requirements for surviving a rouge wave would be keeping structure intact and water on outside through a roll, broach ,pitchpole or being immersed under tons of water.

[osirissail]

Here is a Utube video of a typical day in the western north Pacific and the waves that the USS Kitty Hawk encountered for about 4 days. It is about 100 feet from the keel of the boat to the flight deck level, so you can estimate the size of these waves.
See:

YouTube - Carrier in Big seas

For your Triton to be ready for severe ocean waves look at your cabin windows and ports and deck hatches. It was typical in the olden days to attach "storm" ports outside the boats normal ports. These bolted on to provide impact protection against waves breaking in the plastic windows and flooding the boat.

[S&S]

Originally Posted by osirissail

It was typical in the olden days to attach "storm" ports outside the boats normal ports. These bolted on to provide impact protection against waves breaking in the plastic windows and flooding the boat.

"Olden Days" ?? Just common sense IMO. Big windows would creep me out offshore. I took a pass on a beautful De Dood yawl due to "too much glass". Previous owner did cruise her though (pacific), so there you go.