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Old 05-07-2008, 15:01   #16
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Be wary of people trying to sell a boat, they will exxagerate the speed, and "undere estimate" the weight.

If you look at crossing times in the ARC, not many boats average much more than 6 knots nearly regardless of size. It depends on the crew, how hard they push and of course sea state and wind.

I never plan on more than 66% of hull speed, and carry stores for 40% hull speed. For a 50 footer, 66% of hull speed is around 6.3 knots.

Most of the charter style boats will not do more than around 50% of windspeed, so you can also look at average wind speeds, and not count on doing more than around 10 knots boatspeed for longer periods. With more than around 25 knots of wind on the ocean you will probably be looking at reefing and going more for comfort than speed.

Have a look at the data on the Multihull Dynamics site, buy the figures for the boats you are interested in. They might not be exact but will give you a good picture of how they will perform compared to each other.


Regards

Alan
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Old 05-07-2008, 15:23   #17
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I have a "rule of thumb" I found out for ours, anyway:

It goes about as fast as a bit larger monohull.

We seeing average speeds of 6 knots or so on a small 34' cruising cat. I think our average was 6-7 knots on the 45' mono we had before.
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Old 05-07-2008, 23:56   #18
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Quote:
Originally Posted by Nordic cat View Post
Be wary of people trying to sell a boat, they will exxagerate the speed, and "undere estimate" the weight.

If you look at crossing times in the ARC, not many boats average much more than 6 knots nearly regardless of size. It depends on the crew, how hard they push and of course sea state and wind.

I never plan on more than 66% of hull speed, and carry stores for 40% hull speed. For a 50 footer, 66% of hull speed is around 6.3 knots.

Most of the charter style boats will not do more than around 50% of windspeed, so you can also look at average wind speeds, and not count on doing more than around 10 knots boatspeed for longer periods. With more than around 25 knots of wind on the ocean you will probably be looking at reefing and going more for comfort than speed.

Have a look at the data on the Multihull Dynamics site, buy the figures for the boats you are interested in. They might not be exact but will give you a good picture of how they will perform compared to each other.


Regards

Alan
I doubt very much manufacturers will still underestimate the weight of their cats after the owner of a French manufactured cat sued the producer 4 years ago. the owner won the court case and receved a big som of money as compensation , it is a hear say story but there will be some true in it.
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Old 06-07-2008, 01:59   #19
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Court case

FP were sued in USA courts and a punitive $3.5m USA awarded against them because they ignored the case - that is what I read on a report of the case on the Internet. I am not sure what the issue itself was.
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