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  #1  
Old 08-23-2010, 03:52 PM
CatBuilder CatBuilder is offline
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Lightest Tender/Dinghy/Dink to Carry 6 pax plus luggage?

While I have a moment waiting for some epoxy to cure, I am thinking ahead to the tender to the catamaran I'm building.

I would like a tender that:

1) Is relatively light weight
2) Can carry 6 passengers plus their luggage in one trip
3) Looks reasonably sharp at the dockside

"Nice to haves" would be:

1) Inexpensive
2) Fuel efficient

Can anyone suggest such a boat I can use on davits on the back of a 45' sailing catamaran?

Is there one I can build? Is there one I can buy? Can one be made from ply/glass/epoxy? Is a RIB the only answer?
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  #2  
Old 08-23-2010, 03:55 PM
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gonzo gonzo is offline
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Relatively light weight is hard to assess. You need to come up with a weight maximum. Six passengers plus luggage is a load of about 1200 to 1500 pounds. For fuel efficient it needs to be narrow and long. I would say that at about 18' you can get one.
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  #3  
Old 08-23-2010, 04:15 PM
CatBuilder CatBuilder is offline
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You're right. "relatively light weight" is pretty vague.

My last tender on a smaller catamaran was a Carible L9. The stats were:

RIB Construction
Weight: 115lbs (52Kg)
Payload: 1170lbs (530Kg)

I am expecting something that will not add tremendous weight at the stern of my light, fast cruising catamaran that weighs similar to a Gunboat of the same size. Here are the catamaran specs:

45' LOA (13m)
25' Beam (7.62m)
Weight: 11,900lbs (5,398Kg)


Isn't there fuel efficiency (a little) in planing? Narrow, long and full displacement is definitely my understanding of fuel efficient, but what about burning a lot of fuel for a short time (because the boat is fast and on plane?) Am I thinking incorrectly on that? I'm more of a sailing guy, so I never quite got the powerboat stuff well.
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Old 08-23-2010, 05:24 PM
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gonzo gonzo is offline
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Planing boats use a lot more fuel on the same distance than an efficient displacement boat. Is an 18 foot tender too long? It could be built at about 120 lbs.
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  #5  
Old 08-23-2010, 05:25 PM
CatBuilder CatBuilder is offline
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Ok, I'm interested in the 18 footer. My beam is 25' so it might make sense.
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  #6  
Old 08-23-2010, 06:24 PM
Submarine Tom Submarine Tom is offline
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How about a little catamaran and tow it?
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  #7  
Old 08-23-2010, 06:27 PM
CatBuilder CatBuilder is offline
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Tom, I was thinking that too. Is there such a thing as a little power cat that can carry 1200lbs?
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  #8  
Old 08-23-2010, 06:52 PM
apex1
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Quote:
Originally Posted by CatBuilder View Post
Ok, I'm interested in the 18 footer. My beam is 25' so it might make sense.
It makes sense.

RIBīs are usually very heavy (the collar is heavy) and I doubt a Cat performs well with a 5,5 meter RIB on the back. These boats come at about 400kg upwards, ex engine!
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  #9  
Old 08-24-2010, 12:04 PM
Dryfeet Dryfeet is offline
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Here's what I'd have if I had the space.

http://www.biekerboats.com/Bieker_Boats/PT_Skiff.html
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  #10  
Old 08-24-2010, 04:57 PM
CatBuilder CatBuilder is offline
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Interesting, Dryfeet!

I like the idea of this boat.

It weighs in at 518lbs dry weight, no engine. That's about what a RIB of that size weighs. I wonder if it's possible to get a lighter craft?

Or... is 500lbs ok hanging off the back of a boat?

I'm not quite sure about this, as I've only used larger tenders aboard megayachts I've run. We had an electric crane that took them from the 3rd deck level down to the water, so I was able to use a 30ft Novurania without issue.

This small, 45' catamaran is quite a different story. It will be quite sensitive to weight. I'm working hard to keep her lean while building her. Will 500 (really 700lbs with motor) hanging off the stern cause detrimental problems?
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Old 08-24-2010, 05:02 PM
Dryfeet Dryfeet is offline
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I'd thought it was a bit lighter all up. That's probably too much for you. I was also thinking that you were a bit bigger. I wonder if they can do a smaller version for you?
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  #12  
Old 08-24-2010, 05:16 PM
CatBuilder CatBuilder is offline
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Or even just this version but with less "fancy stuff' involved. Looking at the videos, it's a little hard to make out, but I thought I saw some fancy wood work inside this boat. I wonder if it could be made lighter.

I wouldn't even need the kit - just the plans, since I could probably build it out of scrap from the big boat.
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  #13  
Old 08-25-2010, 02:27 PM
WickedGood
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Cat builder.

where are you?

I have a nice little boat that you could make copies of. Maybe?

see pictures at http://www.boatdesign.net/forums/mar...ran-33159.html


Give me an email and well talk about it

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  #14  
Old 08-25-2010, 04:00 PM
CatBuilder CatBuilder is offline
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I'm not sure that tri could carry 1200+lbs??
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  #15  
Old 08-25-2010, 08:13 PM
WickedGood
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It will carry ten times that when you build a pair of them hulls with a deck between and call it a Catamaran.

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