I was over at Salmon Bay Marine Center (Seattle) the other day and came across this wild looking thing. Certainly not a trawler but it did have twins! (2x1,900 hp MTUs I was told). As best as I could pace off, it was about 135 feet. A very tall boat sitting on those twin hulls. Did not have a builders name on it that I could see. Very stark black & white color scheme.
A Cool Boat
- Thread starter THD
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The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
markpierce
Master and Commander
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- Carquinez Coot
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- penultimate Seahorse Marine Coot hull #6
A running shoe on steroids.
Tad Roberts
Guru
Looks like a Craig Loomis wave piercer......
LOMOcean Design | Naval Architecture and Yacht Design - Pleasure
LOMOcean Design | Naval Architecture and Yacht Design - Pleasure
You stole my thunder, Tad!
VikingBay
Veteran Member
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The Zenith is an Incat Crowther design yacht built at Sabre Catamarans shipyard.
Incat Crowther ? Leisure
Motor Yacht Zenith - a Sabre Catamarans Superyacht
Incat Crowther ? Leisure
Motor Yacht Zenith - a Sabre Catamarans Superyacht
Tad Roberts
Guru
Good find Viking.....somewhere there's a crossover between wave piercer and catamaran....but I'm not sure where exactly it might be this morning....
CPseudonym
Moderator Emeritus
I understand that the owner of a yacht like this would not be overly concerned with fuel burn. Tad can you or someone else explain how to calculate hull speed on a catamaran design hull? Does it double the waterline length for that calculation? Strange and dumb question I'm sure but I've never understood it.
Tad Roberts
Guru
With catamarans all bets are off.....
Most comparison formulas are only useful when comparing apples with apples. Though the same physical principals apply to catamarans and monohulls, different things are happening because the hull forms are so different. A mono hull may have a beam/length ratio of 3:1 or so, a catamaran demi-hull (one half the cat) may have a beam/length ratio of 10 or 12:1. We know that an important factor in resistance is the cross sectional area of any hull, and it's length. These are long and skinny.
Note from Vikings link that top speed is 29 knots and cruising speed 20 knots....but she's 132' long!
In fact things change so drastically once beam/length gets over 10:1, these hulls may not be planning at 29 knots....That is the boat is not lifting, but just sliding along through the water in displacement mode. There are big cats with displacement, semi-displacement, and planing hulls, and I'm not sure which this particular boat is.
You would not double the speed/length calculation for a catamaran unless the the hulls were joined end to end. As they are side by side and both must be pushed through the water the length of one hull applies.
CPseudonym
Moderator Emeritus
Thank you very much.
Sent from my iPhone using Trawler
Sent from my iPhone using Trawler
Tad-thanks for that explanation-I have a hard time imagining that boat planning as she was, according to the hull markings, drawing less than 2 meters at the dock and with each hull as narrow as it is, there would not seem to be enough flat surface to plane. My guess is she must weigh something on the order of 85-100 tons.
