Heavy Weather tactics
There are several other real life heavy weather issues. Seas are often not
from a consistant direction in extremely heavy weather. There are series of
large waves, and series of smaller waves. The question which one has to ask
of a power boat, is it suited to run off under power with or without series
drogues, or is it best to head into the seas? My only experience in really
heavy weather (40 to 45 foot breaking seas and sustained winds of excess of 65
knots for several days) is that my boat was suitable for running off--keeping
the heavy seas quartering off the stern and running down wind down waves. The
boat was deep keel, double ended at the waterline with a windglass transom,
thus lifted fairly fast and there was only one small scuttle which oppened to
the aft. This configuration is similar to Passagemaker. This configuration
is more suitable for running with the seas and potentially taking seas from
the aft sector.
Many of the current breed of passagemakers are flat sterned, relitatively
shallow draft, broad buttock lines, with minimal keel, and often cockpits and
doors which might be more easily breached aft. (This configuration gives more
room in the boat, and more initial stablity, less roll). Thus the question is
when does one stop running and then turn and deploy a sea anchor/para-anchor
vs streaming series drogues which will keep the stern too the sea?
The bow of these modern passagemaker boats is often higher, with a Portugese
Bridge acting as a breakwater and high pilot house windows. Although the
boats seem to have been designed to buck into seas--the reality is that this
is true up to 15 or so feet, not 45 footers. The forces of heavy seas are
very hard to understand. 1 1/4" SS pipe railings are easily bent. Items can
be washed off the deck. Dave relates rolling and pitch polling. Many boats
which have been subject to these have basically had the deck washed
clean--life rafts, dinghies, any containers on deck are torn loose. The other
factor is that it is not just a boat rolling if caught broad side to a sea
(for example when we took a 90 degree roll, we were running at about 150
degrees to the seas, one of these waves from a different direction caught us
from the side and caused the roll), But much of the damage is not only caused
by water breaking on the boat--but by the boat falling off the wave onto the
sea below--again large waves.
We all wish that weather forcasting was perfect. It is not. Once you have
committed to a passage, especially in high lattitudes, storms may not be as
well predicted, and there is not time to change course to miss the storm.
Another part of the issue is the fuel in a passagemaker--a reserve may be
consumed in either running off, or attempting to buck into the seas.
These extreme seas are very unlikely to be encountered in coastal
cruising--but more likely in long passages. Ken is absolutely correct, that a
power boat uses the routes which are noted in the Ocean Passages for the world
for low powered vessels--sailboats tend to go with the wind aft of the beam
(not just where it is windy)--but so do low powered passagemakers--as well as
cutting across the major highs (which are calm). When I was in an extreme
storm in the North Atlantic, we met another boat in the Azores, which had the
range under power to go from the Virgin Islands directly across the Atlantic
High and avoided any heavy weather. So it is not just "enough" range, but
enough range to make those longer hauls which might give a chance of better
weather.
As for loss of life on sail vs power--not enough power boats doing passage
making to have any really meaning statistics. My own experience is that one
the the greatest risks is being run down--that is lessened with modern
electronics. As AIS becomes economical it will be on all passagemaking
boats--sail as well as power. Don't under estimate the nav gear on some
sailboats. But many sailors are doing the trips on a much lower budget.
Bob Austin
Bob Austin
Bob:
Great post.
I must confess that I've never personally seen either a drogue or a sea
anchor, so forgive my rookie questions about them.
I'm commissioning my new boat now, and deciding what safety equipment to
buy. I take it from your post that you recommend carrying BOTH a drogue and
a sea anchor? (assuming one has the budget and space required)
To verify that I understand correctly the circumstances under which I might
use one or the other:
-
The most likely circumstance under which I might use a sea anchor would be
if I found myself dead in the water and wanted to keep my nose into the
wind. -
A drogue could be used in a following sea if I were having trouble
steering. In particular: if I find myself speeding down the back side of
waves and am worried about getting spun sideways and rolled over.
I was curious about what these things are like to deploy or pull back into
the boat, and found this link to an instruction manual for a Sea Anchor:
http://www.seaanchor.com/pdf/sea_anchor_instructions.pdf I found it
worthwhile reading, and inadvertently amusing at times.
In all of my research (googling) I found virtually no references to use of
any of these devices with a power boat. I'm not at all certain they are even
made for my boat. The tables showing recommended drogue sizes stop at 60,000
pounds, and my boat weighs nearly 200,000.
Some interesting reading on drogues can be found at:
http://seriesdrogue.com/coastguardreport/droguereport.htm
My current thinking is to buy both, perhaps experiment once with their use,
pack them away, and then work hard to ensure they are never used again.
Ken Williams
Ken,
I am a new list member, but wanted to jump in here for 2 reasons.
-
I have found a reference book called the "DRAG DEVICE DATA BASE" by
Victor Shane quite useful in explaining tactics for the use of sea anchors
and drogues. It is rather more technical than salty, but lots of good info. -
Your new boat and my new Selene are crossing the Pacific together. I'll
contact you off list for more about this.
Regards,
Dave Pabst
Selene 53
Duesie
Manchester, WA
-----Original Message-----
From: passagemaking-under-power-bounces@lists.samurai.com
[mailto:passagemaking-under-power-bounces@lists.samurai.com] On Behalf Of
Ken Williams
Sent: Friday, April 06, 2007 9:17 AM
To: 'Passagemaking Under Power List'
Subject: Re: [PUP] Heavy Weather tactics
Bob:
Great post.
I must confess that I've never personally seen either a drogue or a sea
anchor, so forgive my rookie questions about them.
I'm commissioning my new boat now, and deciding what safety equipment to
buy. I take it from your post that you recommend carrying BOTH a drogue and
a sea anchor? (assuming one has the budget and space required)
To verify that I understand correctly the circumstances under which I might
use one or the other:
-
The most likely circumstance under which I might use a sea anchor would be
if I found myself dead in the water and wanted to keep my nose into the
wind. -
A drogue could be used in a following sea if I were having trouble
steering. In particular: if I find myself speeding down the back side of
waves and am worried about getting spun sideways and rolled over.
I was curious about what these things are like to deploy or pull back into
the boat, and found this link to an instruction manual for a Sea Anchor:
http://www.seaanchor.com/pdf/sea_anchor_instructions.pdf I found it
worthwhile reading, and inadvertently amusing at times.
In all of my research (googling) I found virtually no references to use of
any of these devices with a power boat. I'm not at all certain they are even
made for my boat. The tables showing recommended drogue sizes stop at 60,000
pounds, and my boat weighs nearly 200,000.
Some interesting reading on drogues can be found at:
http://seriesdrogue.com/coastguardreport/droguereport.htm
My current thinking is to buy both, perhaps experiment once with their use,
pack them away, and then work hard to ensure they are never used again.
Ken Williams
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