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Jeff
 
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Default Why do people buy cruising catamarans ?

Evan Gatehouse wrote:
....



Incidences of cruising cats are pretty infrequent. I only know of the
following;

- PDQ 32 capsizing while entering a cut in the Bahamas while a "rage"
was blowing. Pitchpoled in very shallow water in the huge breakers


I talked at length to the owner of this boat shortly after the
episode. Apparently, the charterer was singlehanding, on autopilot,
and down below. He was carrying full sail (one report said one turn
on the jib) in 25+ knots, sheeted in tight, while on a beam reach. He
was not entering, but passing by a notoriously windy cut in the Abacos
(by Whale Cay?) and got hit by an estimated 45 knot gust and 6 foot
wave beam on. The boat did not pitchpole, but slowly went on its
side, and stayed there for several hours while the owner (who came
from Marsh Harbor?) and others tried to right it. Finally, a stay
broke and it capsized. It was towed back to Marsh Harbor where the
deck was trashed by efforts to lift it inverted with slings. I saw
the boat in Toronto awaiting a deck rebuild.

One design factor considered by cat builders is how much wind could a
boat handle in such a worst case of a gust on the beam with full sail
sheeted in. The figure used for the PDQ 32 is 45 knots. The
assumption is that in almost all cases where 45 knots is possible, you
would shorten sail - even a single reef makes a huge difference in
this situation. Also, in most cases someone would be on deck to
release a sheet. A significant lesson is that whenever full sail is
sheeted in during a blow, someone must be on deck!

Two other factors apply he First, this particular boat was sailing
"light." That is, it was stripped out and not carrying cruising gear.
If it were loaded, it probably would not have gone over. The second
is that this design has a rather narrow beam, coupled with a tall
profile. This is one of the issues with smaller cats, since the
temptation by designers is to make them narrow enough for a slip.
Also, since the bridge deck clearance and overhead boom height have
practical minimums, smaller cats have proportionally taller rigs. The
combination of narrow beam and tall rig makes this sort of incident
inevitable. For this reason, I've usually said that the minimum size
for an offshore capable cat is about 35 feet, unless it has a very
conservative rig.

This situation also applies to the Gemini (14 foot beam), and a recent
case of an Iroquois (which only has a 13 foot beam!). The Heaven
Twins is another such case, with a beam under 14 feet.




- a Gemini capsizing in Texas; sailed over due to too much sail

- a Fountaine Pajot 35 capsized in the Caribbean; sailed over with a
charter group aboard

- a Catana in the Med; capsized due to a sudden squall hitting with the
chute up at night.

- a Heavenly Twins 26 or 27 capsizing in Force 10+ north of the British
Isles during a rare summer severe storm.

I have also heard of the F-P Maldives 32 being pretty susceptible to
capsize but that's more innuendo that actual facts and the Iriquois but
I don't know if they were capsized during racing or while cruising.

Most of the above are smaller, narrower beam cats by the way of fairly
old design; the exceptions being the FP 35 and the Catana.

When the Wolfson Unit of Southhampton University did a study of trying
to capsize cruising cat models the only way they could do it was a beam
on breaking wave beam of the boat (similar to a monohull by the way)

"MODEL TESTS TO STUDY CAPSIZE AND STABILITY OF SAILING MULTIHULLS"
Deakin B.
The 15th Chesapeake Sailing Yacht Symposium, January 2001

Evan Gatehouse