Some brief thoughts [very brief] on wave piercing catamarans.

Wavepiercers:

A wave piercer is a displacement catamaran. The hulls of all displacement
catamarans cut through the water.So to that extent they are all
"wavepiercers". So, provided that the hull parameters such as displacement,
displacement/length ratio and the speed/ length ratio are the same for the
normal catamaran and the wave piercing catamaran, then the power and
fuel consumption of both types will be exactly the same. The naval
architecture ie: what is under the water, is identical.

However there is a difference in how each type distributes its reserve
buoyancy ie: above the water, and this is what gives the different
appearance. this will also result in different behaviour in different sea
conditions.

The wavepiercer is a little more complicated and will probably be slightly
more expensive to build. It may also have a little less accommodation than
the same sized normal displacement power catamaran.

In the pleasure boat arena [as opposed to commercial vessels] the wave
piercing concept was originally a styling exercise for a client who did not
want his catamaran to look like a catamaran. In meeting this requirement it
has been very successful!

There are also a number of different types of wave piercing catamarans. From
the very extended bows of the Gold Coast Yachts vessels to the rather
smaller "Z" bows. There are also the types that have "normal" catamaran bows
underlaid with extended "wavepiercing" bows. This is usually done in an
effort to increase the waterline length while hopefully saving weight.

Regards,

Malcolm Tennant.  ARINA  MA

Malcolm Tennant Multihull Design Ltd
PO Box 60513 Titirangi,
Auckland 1007
NEW ZEALAND

ph +64 9 817 1988
fax +64 9 817 6080

e-mail malcolm@tennantdesign.co.nz
www.tennantdesign.co.nz
www.catdesigners.com

On Mar 28, 2006, at 6:59 PM, Malcolm Tennant (by way of Georgs
Kolesnikovs) wrote:

Some stuff about wave piercing power cats. I thought that a few of
you may not have seen some of the big ones, 90 Meters. InCat in
Australia makes ferries and modified hulls for navy, etc. See one of
them at:

http://www.incat.com.au/news/media.cgi?task=SHOWCATEGORY&category=63452#

I hate to think what it costs to run one of these, but what a way to
travel, and at 40-50 knots, too!! You can take your caravan/RV,
Helicopter and 40 foot dinghy with you for local travel and have
plenty of room for all the relatives and even some of their friends.

Seriously, these big cats must be providing lots of data for Naval
Architects in their travels around about the world.

Fair winds and happy bytes, Dave Flory, San Jose, CA.

Speak softly, study Aikido, & you won't need to carry a big stick!
See my photos @ http://homepage.mac.com/dflory

I'd surely hate to have to foot the fuel bill for that rig!!!

D C "Mac" Macdonald
m/v Another Adventure
Grand Lake - Oklahoma

----Original Message Follows----
From: David Flory daflory@speakeasy.net
Reply-To: Power Catamaran List power-catamaran@lists.samurai.com
To: Power Catamaran List power-catamaran@lists.samurai.com
Subject: Re: [PCW] Wave Piercing displacement catamarans.
Date: Tue, 28 Mar 2006 20:33:29 -0800

On Mar 28, 2006, at 6:59 PM, Malcolm Tennant (by way of Georgs
Kolesnikovs) wrote:

Some stuff about wave piercing power cats. I thought that a few of
you may not have seen some of the big ones, 90 Meters. InCat in
Australia makes ferries and modified hulls for navy, etc. See one of
them at:

http://www.incat.com.au/news/media.cgi?task=SHOWCATEGORY&category=63452#

I hate to think what it costs to run one of these, but what a way to
travel, and at 40-50 knots, too!! You can take your caravan/RV,
Helicopter and 40 foot dinghy with you for local travel and have
plenty of room for all the relatives and even some of their friends.

Seriously, these big cats must be providing lots of data for Naval
Architects in their travels around about the world.

Fair winds and happy bytes, Dave Flory, San Jose, CA.