SailNet Community - View Single Post - Heaving-To versus Bare Poles
View Single Post
  #23  
Old 07-30-2008
johnshasteen's Avatar
johnshasteen johnshasteen is offline
Senior Member
 
Join Date: Aug 2002
Location: Houston, TX
Posts: 649
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 12
johnshasteen is on a distinguished road
Quote:
Originally Posted by GrahamCownie View Post
Johnshasteen. Well, here's the interesting bit that hadn't realised before about the risk or othwerwise of being pooped. To quote from Jordan's site:

"In addition to a feeling of helplessness, there is another irrational attitude that countered our obtaining a solution to the capsize problem. The shape and motion of storm waves when viewed from the deck of a yacht are such that it can lead to optical illusions which confuse the skipper. A large storm wave approaching the boat appears to be a dangerous wall of water and the skippers instinctively tend to head up or run off to avoid being pooped. Actually the water in the wave is not moving towards the boat and will lift the boat harmlessly"

Jordan then goes no to say:

"Another optical illusion is that it is possible in a survival storm to reduce the hazard by running off before the waves and, by skillful seamanship, to out maneuver a dangerous wave. This is a particularly unfortunate choice. The waves are moving faster than the boat can go. A 40 ft .breaking wave will be moving at a speed of approximate 23 knots. The breaking wave is completely random. Furthermore, by far the most important concern is that, if the boat is moving through the water, the chance of being caught by the wave and surfing to a dangerously high speed is greatly augmented".

And finally:

"A final misconception is the belief that a breaking wave "strikes" the boat and that the moving water in the crest does the damage. Actually, the boat is lifted by the forward face of the wave with no impact. When it reaches the breaking crest the boat velocity is close to the wave velocity. The crest water is aerated and has little damage potential. Damage to the boat is incurred when the boat is thrown ahead of the wave and impacts the green water in the trough. The leeward side and the deck are struck. A careful reading of "Fastnet Force Ten" and "Fatal Storm" will confirm this conclusion".

It maybe we're talking about two differnet things here: a survival storm versus something not quite so life threatening. But the wave mechanics can't be too different.

I've not yet had the "pleasure" of running before a storm but I did spend a very uncomfortable night bashing head on into a Force 9. It was OK for 8 hours or so but I can't imagine how a shorthanded crew could do it for days on end. Even in conditions less than a survival storm I'd be tempted to put the drogue out and go below for a kip.
Interesting stuff, but our crew (in both storms) three of us, with a combined 100+ years of offshore sailing in the Gulf, Atlantic and Great Lakes, had no optical illusions or misconceptions about either storm (we actually thought the winds in the March storm were around 40-50 and the seas 18-20ish - the conditions were in fact, according to Coast Guard New Orleans, winds 50-60 and gusting higher and seas 30 feet.
When the sustained wind is above 40, you have to change from sailing to surviving. To the amazement of CG New Orleans and CG Corpus Christi, we "survived" the first storm for 48 hours and the second for 36 hours (both felt like an eternity) - the first question they asked when we were back in port and I called them was, "do you have an EPIRB" - I answered yes - then they asked why we hadn't deployed it. So, while I respect Jordon, every storm is different, every boat is different, every crew is more/less capable. The best you can hope for is that you don't ever get caught in a major storm - but if you are so unfortunate as to get caught in one, you have to play the hand that you're dealt at the time.
__________________
s/v Paloma, Bristol 29.9, #141
Slipped in Bahia Marina, easy access to Corpus Christi Bay and the Gulf of Mexico.
Reply With Quote Share with Facebook