Cruisers Forum

  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
Thread Tools Search this Thread Rate Thread Display Modes
Old 28-11-2011, 17:52   #16
Registered User

Join Date: Sep 2009
Location: on board, Australia
Boat: 11meter Power catamaran
Posts: 3,648
Images: 3
Re: Bareboat to Full Load: What Does it All Weigh ?

Originally Posted by rgesner View Post
Thanks for all your helpful comments, keep 'em coming.

It is becoming clear that the boat builders overestimate the draft and bridgedeck
clearance (if they even list it) by specifying them only with an unloaded boat, and/or
specifying them with an unrealistically light load to DWL.

It is getting frustrating trying to find a truly long-range bluewater capable cat of 40'
or less with a good layout which can retain sufficient clearance and good
performance with a reasonable full load of 6000 to 8000 pounds.

A 40ft cat that can handle a full load of 8000 lb is not likely and you would need to go to 45-46 ft vessel.

As barra said 250kg/cm immersion for the leopard would be as good as it gets.

Most 40ft production cats also have insuficient fuel for really long range crusing without carrying jerricans and chasing fuel.
downunder is offline   Reply With Quote
Old 28-11-2011, 19:17   #17
CF Adviser
Intentional Drifter's Avatar

Join Date: Apr 2006
Location: Pac NW
Boat: Boatless, for now, Cat enthusiast
Posts: 1,317
Re: Bareboat to Full Load: What Does it All Weigh ?

Hi, Rgesner, and welcome to CF --

If you're looking for "everything" in a cat (or mono), then yes, it is indeed frustrating. For just about every decision made, there is a compromise involved. In order to get a greater payload, you are looking at either a longer boat (more $$$) or fatter hulls (less performance). No way around it. You can compensate a bit with the fatter hulls by increasing sail area, but that also involves a taller mast, stronger (heavier) rigging, and of course greater weight aloft, so you've "lost" some of the payload gained in order to keep your performance constant.

You might want to prioritize what you want in a boat and start looking at ones that fit more in line with those priorities. If light air sailing and top average speed isn't all that important to you, then you can increase your payload capacity without costing you an important priority. You will tend to pay for that decision in other ways, though. Such boats tend to have bigger engines that require bigger fuel tanks (if you're going to have a decent motoring range) and you will use them more, because the boats won't sail very well in light wind, so you motor more. (In fact, I would say that we encounter far more light wind conditions than heavy. Unfortunately, the boat needs to be able to cope with the latter in order to keep you safe.)

If you are really a performance oriented sailor, then you compromise the luxuries. Simply look at the speed machines and you can tell that they are pretty darn spartan and have considerably less internal room. Again, you can compensate for this -- some -- by using light weight materials (e.g., carbon = $$$). You can also be an absolute weight-watching obsessive. But, the problem here for liveaboard cruising is that if you're going very far away from civilization, then you also need to be pretty self-sufficient, and that means taking a lot of stuff with you.

So, I suggest that before you pull out the rest of your hair, first come to an awareness and agreement with your liveaboard crewmates about what's absolutely important, what would be good to have (but willing to give up), and what you really don't care about. That will help you get started.

By the way, on your list, I noticed that you have some details that seem out of whack to me: 250 lbs for an outboard and fuel (Get a 15hp Yamaha 2-stroke, not only are they incredibly reliable with parts available everywhere, they weight 75 lbs. 12 gallons of gas is about 75 lbs., so that saves you 100 lbs.) 150 lbs of propane is a lot of propane and will last a very long time. A 40 lb bottle lasted us for months. Depending on the efficiency of your boat and engines, you may be over-estimating the amount of fuel you need on board. Our boat gets .67 gph per engine. 1 engine gets us 6.5 knots (so long as sea state and currents are agreeable). 100 gallons gives us a theoretical motoring range of 1000 miles. Not enough to get us across an ocean, but that's what the sails are for.

A big area of potential weight savings is going to LiFePo4 batteries -- more amp/hrs, higher charge acceptance, and 1/3 to 1/2 the weight. I calculated that by making the switch I could increase my usable power budget by 50%, reduce charging time by 50%, and take off half the weight of my gel cells, thereby increasing my payload by about 300 lbs.

Intentional Drifter

Observations are gold; hypotheses, silver; and conclusions, bronze.

Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote.--Ben Franklin

Everyone is entitled to their own opinion, but not their own facts.--Daniel Patrick Moynihan
Intentional Drifter is offline   Reply With Quote
Old 28-11-2011, 19:35   #18
Registered User

Join Date: Nov 2011
Posts: 202
Re: Bareboat to Full Load: What Does it All Weigh ?

Thanks, I'll take a look. Have you looked at the Maverick 400? It has rather wide hulls, giving it a lot of room and capacity for a 40' cat, but seems very well designed and by all reports performed well.

Originally Posted by Barra View Post
check out the Leopard 39 - im dealing with the same issue and at 250kg per cm immersion its about the best ive found under 40 feet. started a thread on this couple of days back
rgesner is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Battery Charging with Load Applied = Incorrectly Charged Batteries Fuss Electrical: Batteries, Generators & Solar 11 31-08-2011 11:44
Southern US Bareboat Companies malyea Atlantic & the Caribbean 0 30-08-2011 04:50
My Battery Load Test Results - Advice, Please ? Poozer Electrical: Batteries, Generators & Solar 8 21-07-2011 04:48
Zero to Full in No Time At All! capngeo The Sailor's Confessional 12 03-07-2011 23:06
Voltage drop under load, amps read 99% ?? VVD Electrical: Batteries, Generators & Solar 25 28-06-2011 15:25

Advertise Here

All times are GMT -7. The time now is 11:57.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.