Payload of 30 feet monohull boats?

[Pete7]

Think the op needs a 45ft trawler for this purpose.

Pete

[GTom]

Originally Posted by Pete7

Think I would choose the petrol version for ease of use, but not the coltri model. Had one of those in the diving club and we killed it, stripped it very carefully and rebuilt it slowly but it still didn't run well afterwards. At another club we had the German Bauer, very old and worked hard. It just seemed to keep going with all the abuse a club could throw at it.

Agreed, the Bauer Oceanus might be the best suited model for the job.

Think the op needs a 45ft trawler for this purpose.

. More precisely: Trawler, circumnavigator's edition.

[Jim Cate]

Originally Posted by GTom

Thanks for all the valuable thougts. It sounds that with careful boat & crew selection the combination of 4 people + scuba + longer passage + <10m LOA is not completely impossible. I am currently looking at Elan 340's, they seem to be roomier than most 30-33' models while staying below 10m, where most marina prices go mental.

GTom, looks like you are only hearing that which favors your plans. I do not reach the same conclusions from reading the posts OR from my own experience in cruising in a 30 foot yacht. Perhaps it is physically possible to cram all the stuff that you mention into such a small boat, but to then practically operate it, and safely operate it and enjoyably operate it... well, big disconnect in my eyes.

As one who has actually cruised and made long passages in a 30 foot yacht (Yankee 30), I think you need to remove the rose colored lenses from your dive mask!

Oh... I have not experienced a big change in marina costs at the 10 meter size point. Prices seem to be reasonably linear with size in the marinas I've used (admittedly not in the USA in recent years).

Jim

[boatman61]

GTom.. your biggest problem is going to be suitable storage space.. the Elans are like Bene's etc.. shallow bilges and limited cockpit locker space with the aft cabin area.. most usable space is taken by tankage and boat systems leaving only limited locker and wardrobe storage..
Leave the tanks at home and buy 4 in SXM when you have crossed the Atlantic.. the hose's, gauges etc take less room separately.
You'll need a fair bit of space for food, extra water etc.
Now if you were talking about a Westerly.. they'll store as much as 3 Elans..

[buzzstar]

Originally Posted by frogvalley

My 36 foot sailboat is documented, listed at 16 tons. Thats long tons, a measure of volume not weight. She weighs 8 tons...

A step in the correct direction! Subject to the better informed opinions of others, as initially used, the word was tun. A tun was a barrel of a specific size, and vessels were measured (taxed too?) by the number of tuns they could carry. Over time the word has become "tons," and it is used for (I am unsure) but is used in documentation by the USCG, and probably elsewhere in the world.

As to you statement about "rated." I do not think so, but could be incorrect. The number of adults a boat will sleep relates to the number of berths, and is typically used for advertising and evaluation by potential buyers.

I do recall that one of the design aspects of boats (perhaps all, but most of my knowledge relates to sail powered vessels) is the mass (weight) that will cause the vessel to sink one inch deeper (I am sure centimeters or millimeters are used in most of the world today). This can be important to a sailboat because they spend so little of the time while moving under sail on an even keel. Many (most?) are designed to take that into consideration, and in fact sail better on a tack.

You may want to do your own research, and maybe Google a few terms such as displacement, and try a some websites that provides sailboat data. Have fun, and keep asking questions.

AFTER POSTING I REALIZED I HAD SKIPPED READING A BUNCH OF PREVIOUS POSTS. SORRY FOR ANY REDUNDANCY.

[a64pilot]

I had a 36' fifth wheel camper that I think was rated to sleep 12 or something crazy, of course if they all inhaled at the same time I think it would crush it.
If by tanks we are talking aluminum 80's then by all means just buy or rent when you get to where your going. They don't cost much and can be sold for likely half what you bought them for. A year or two ago an aluminum 80 in hydro was worth $100.
Compressors are only really needed if your somewhere you cannot get fills, and of course a compressor is just air, not Nitrox or Trimix, and I will only dive air if there is no other choice

[GTom]

Originally Posted by boatman61

GTom.. your biggest problem is going to be suitable storage space.. the Elans are like Bene's etc.. shallow bilges and limited cockpit locker space with the aft cabin area.. most usable space is taken by tankage and boat systems leaving only limited locker and wardrobe storage..
Leave the tanks at home and buy 4 in SXM when you have crossed the Atlantic.. the hose's, gauges etc take less room separately.
You'll need a fair bit of space for food, extra water etc.
Now if you were talking about a Westerly.. they'll store as much as 3 Elans..

Buying tanks/other bulky+heavy+cheap equipment near the destination is a good idea. Reducing the crew for the passage from 4 to 2-3 will do even more - I'll most likely follow that route (2 flies 2 sails). Choosing the first boat seems to be a messy business, if someone has multiple agendas.

[buzzstar]

Originally Posted by buzzstar

A step in the correct direction! Subject to the better informed opinions of others, as initially used, the word was tun. A tun was a barrel of a specific size, and vessels were measured (taxed too?) by the number of tuns they could carry. Over time the word has become "tons," and it is used for (I am unsure) but is used in documentation by the USCG, and probably elsewhere in the world.

As to you statement about "rated." I do not think so, but could be incorrect. The number of adults a boat will sleep relates to the number of berths, and is typically used for advertising and evaluation by potential buyers.

I do recall that one of the design aspects of boats (perhaps all, but most of my knowledge relates to sail powered vessels) is the mass (weight) that will cause the vessel to sink one inch deeper (I am sure centimeters or millimeters are used in most of the world today). This can be important to a sailboat because they spend so little of the time while moving under sail on an even keel. Many (most?) are designed to take that into consideration, and in fact sail better on a tack.

You may want to do your own research, and maybe Google a few terms such as displacement, and try a some websites that provides sailboat data. Have fun, and keep asking questions.

AFTER POSTING I REALIZED I HAD SKIPPED READING A BUNCH OF PREVIOUS POSTS. SORRY FOR ANY REDUNDANCY.

At a site called calculator .com I found a figure for a Benteneau 31 (I think it was) which, among other things indicates the weight needed to deduce the draft by one inch. It as something like 932 pounds, but I strongly suggest doing your own research since I did not write anything down after looking and before writing this. When I was looking, I was not impressed with this model as a cruising vessel, but that is just personal opinion since it is not for me to decide.

[Tkeeth]

5 guys, 4 days in hunter 430 with food and personal gear wasnt bad starting out, but i think nerves were raw by the end.....i agree, space goes before weight.

[Seagirt]

Thanks to all who posted. I read it through last night and then got absorbed in the two links posted below. My apologies if those links were posted previously in this thread (I've already forgotten what I read last night).

Sail Calculator – Tom Dove

Sail Calculator Pro v3.54 - 2800+ boats

Once the information for the boat in question is entered there are ratios computed and some context as to what the numbers mean. Among others the pounds per inch immersion is calculated.

So, 650#/inch for my c&c 25. But I still don't know what my safe payload range would be.

[rpjn59]

First off, I personally would not want to do long term cruise or crossing on a 30 ft. Boat with 4 adults plus extended gear, there just isnt enough room in my opinion. One thing to consider is rating as stated previously ppii, pounds per inch immersion. This mostly has to do with the foot print of your boat at the waterline, the hole it punches. 30 ft boat is most likely between 700 to 1000 pounds per inch. The other issue is where this weight is placed, both as dead weight and potential windage. This will also affect the sailing characterists and safety.Pretty much any weight you add to the boat will add negatively to roll over specs also, so limiting it is usually best. But we have to practically especially when cruising we are going to need gear and supplies, lower is always better. Take a look at some you tube vids of what couples on small boats look like when they're supplied up for a cruise, good thing someone has to be on watch because there isnt much room below.

[rpjn59]

Hey again, another thing to consider is what definitions for tonnage is by the coast guard or what ever govn. body. Here in the U.S. some people get the difference btw displacement, net tons and gross tons confused, ie. The displacement is not the net tons. On the CG web site they give the definitions. I recently meet a guy who thought his boat was a battle axe of the seas because he assumed that the net tons was the displacement of his boat and there for built very robust. Some advertising ads of used boats make this error also. I found when checking specs on boats it worth looking at more than one source and also the original manuf. ref.
Fair winds...

[first wind]

Originally Posted by Tetepare

Am I misreading? How do four people equate to four tons?


A post-race party last summer I saw 35 people on a 35' sailboat. At the dock. And it was pretty low in the water.


My friend on his Catalina 30 regularly has multiple guests with dive tanks, etc.


I don't see where four people with dive gear on a 30' boat is any cause for thought.

he is thinking about people plus the weight of food, clothes, basic personal items, water...basically all of the additional weight it takes for four people to live for a passage on a sailboat. if you are only day sailing, then you only need to worry about the weight of the people (and dive gear, if that's you thing).

[MarkusK]

Originally Posted by MarkSF

I was aware that, as a nation, the average weight has been increasing over the years, but I didn't realise it had got that bad.

Originally Posted by Sailmonkey

If we tried to put 6 people on our 32' boat for an Atlantic crossing I can guarantee I would "lose" 2-3 of them along the way.......there's just not enough room!!!

CF is a great place for gaining knowledge, but a good chuckle is always welcome. Good one guys.