Cruising couple payload

[tp12]

Hello again ..

So, I've been reviewing a lot of cat designs but I'm having trouble relating the payload weights to spec/loading for a cruising couple.

Does anyone have an accurate understanding, through actual weighing of the boat in cruising trim and also empty (from launch maybe?)? If I get a view of someones setup I can add and subtract and play around with it based on weights for various equipment/toys etc.

Something to help give me a rough idea so I can rule out boats that won't carry what I want to carry would be awesome.

Thank you.

[HankOnthewater]

There are 3 issues at play here:
1. The lightship displacement. This displacement is generally the figure quoted in brochures, but it is without: people, their stores, tender, outboard, liferaft, and in many cases without any add-on equipment. In this lightship figure tanks are certainly not filled, but may have some water and fuel. I can’t recall the exact definition of lightship re tankage.

2. Pounds per inch immersion, or millimetres for the metric minded: how many lbs/kg is needed will to ‘sink’ boat the boat 1 inch/10 mm. If this figure is quite low then that boat can be overloaded easily and sail characteristics will be adversely affected. For more info see: Ted Brewer Yacht Design
It shows how to (roughly) calculate the immersion number.

3. How much gear, spare parts, toys, tools, books, food, how many people, how much water and fuel one wants to load on the boat?

How much does one usually take on board? You can do your own sums.
- Fuel and water
- Propane, outboard fuel, oil
- Dinghy, plus oars, plus outboard
- Extra groundtackle: anchor chain, rodes, larger winch
- Extra lines, fenders
- Toys: fishing and diving gear, pushbikes, kayak
- Equipment: watermaker, bowthruster, genset, radar, HF radio
- Add-on items: davits, sternarch, doghouse, teak deck, liferaft
- Many tend to oversize things: rigging, anchor chain/rode
- Food stores
- If one is so inclined: alcoholic beverages
- Clothing and personal gear
- Spares and tools
- Extra batteries and charging equipment like solarpanels and wind genny
- Extra water and fuel in containers/bladders
-
One will find that for a 40 ft boat with 2 persons, that sum will come often to 3 tons (6600 pounds) or more.

[UNCIVILIZED]

tp12,
Unless you do something grossly foolish, I have trouble seeing overloading a 15m catamaran, if that's what you're in fact "driving".

That said, here are a few thoughts:
- Firstly, as already mentioned, break things down into the basic categories, & then look @ what's reasonable, weight wise in each one.

- The Pardey's, I believe, advocate allowing about 1,500lbs per person, including; gear for the boat, personal gear, stores, etc.
Which seems to work +/- based on the boat type (ie; watching weight more on a multi) & length of cruise.

- Go back, & dig through some of Evans Starzingers posts on this topic from a year to two ago, when they were thinking about downsizing instead of simply selling Hawk. And some of said posts may be over on Sailing Anarchy Forums.

- Peruse Richard Woods's site, as I'd imagine that such info has been written down/calculated by designers & would be builders, many a time.


PS: Once you get north of having a 1 ton payload, it's really about choosing what you "want" to carry, vs. whether or not the vessel is big enough. Well, unless you're hauling freight for $ that is.

[Dulcesuenos]

I will say some cats handle loads differently. We've owned 2 38 charter style cats both had roughly a 5k lb load/ cargo capacity. The lighter cat we currently own has settled much less in the water with the same amount of cargo on board. So my thoughts are that not all boats handle the weight the same. Some are affected much more than others for the same actual payload and close to same rating. We do have a good watermaker so we can keep the water tanks lighter, and bought a much lighter dinghy etc but we have lots of stuff on board, toys , spares, etc We are pretty close to our max maybe 1000 lbs below.

Sent from my LG-LS980 using Cruisers Sailing Forum mobile app

[monte]

The official payloads quoted by manufacturers have little to do with the practical application. That said, some designs handle additional weight better than others. Older designs with the sugar scoop close to the water tend to be more bothersome as the sea level can rise to continually cover the lower step, causing cleaning problems, drag and possible water ingress. Most newer designs seem to have a slight freeboard with squared off transom up to 6" that solves the problem aseptically at least. Any weight savings will be directly proportional to the boats performance, regardless of size. On our lagoon 400 we are floating comfortably with a comfortable amount of gear, but I would be hesitant to add more weight, even though a generator and dive compressor and some other toys would be nice at times. Our last day was a lagoon 380 and was floating quite low, close to the step with the same amount of gear on board. I guess I would estimate we have around 1000kg of personal gear and toys and another 1000kg of food and supplies and additional cruising gear such as anchors, water maker, life raft etc for the two of us plus our dog.
A watermaker is a good addition as it means you can cruise with close to empty tanks and save carrying 500kg. The last long passage we did was in the company of two other L400s and we all arrived within a half day of each other after 21 days/3000 miles. We were lightly loaded and one was sitting an inch or two lower in the water with food and supplies for 6,including school books for 3 and a generator, so the additional tonne or so didn't have much adverse effect in the grand scheme of things. Probably sailed a little more aggressively to make the difference.
Usually the heavier the boat, the less effect some additional gear will have on it. Our boat is 10.5T so a couple of tonne of gear is acceptable. If I was going to buy a higher performance cat I would probably be looking for one around 50' with a similar weight and payload and accommodation layout.
A while ago I was speaking with an owner of a new outremer 45 who was complaining to the factory of poor performance. They told him he was overloaded and couldn't expect any better unless he removed some of the weight. Looking around the boat there was much less onboard than we have or had on our L380 and it would have been impossible to shed any weight.

[barnakiel]

Our friends had their boat unloaded when in the boatyard about half way thru their circumnavigation. All their stuff was placed in a container. After refit they moved the necessities back to the boat and sent the remaining part home in that same container.

There were roughly 2t of stuff unloaded. The crew were two adults and a toddler. The boat was a 47ft cat.

They traveled this light as they could afford buying/selling off stuff as necessary along the way. You will carry more when you have to or want to drag along things that can be easily purchased anywhere in the world.

Cheers,
b.

[DotDun]

I've found how the boat is loaded is just as important, or more so, than total weight (barring complete overload). Between fuel tank and jerry cans, I can carry 460 liters of fuel, all that weight is aft. When I do, I have to fill the fresh water tanks (600l) to get more weight forward and balance out the boat. I find very little difference in speed between lightly loaded fuel/water and full load of both. But, it's very noticeable when it's an unbalanced load. It's more noticeable with full fuel and light water than the other way.

Stay within design specs and balance the load, all is good!

[Boatguy30]

The payload comes directly from the waterline plane area not the displacement. So the fatter the hulls at the waterline, the greater the payload. IE pounds per inch of immersion.

[UNCIVILIZED]

Originally Posted by Boatguy30

The payload comes directly from the waterline plane area not the displacement. So the fatter the hulls at the waterline, the greater the payload. IE pounds per inch of immersion.

Yeah, I was just going to make the above comment myself. It's really not tough to calculate/take a SWAG @ one's waterplane cross section, & then figure your immersion rate.

Also, the full stipping out of the boat is SOP for any races of significance. And for heavily campaigned boats, it's done after each day's sailing or practice.
When you first start doing it, you find all kinds of crap on the boat, which you wonder why it was even there to begin with.

On the weight of gear thing, I can see the 1T per person, on a bigger boat. Assuming you carry a full load of chain & several sets of full sized ground tackle. Lots of H2O, fuel, food, & toys, etc.

Though, there is a flipside to such... the less entertainment type of equipment & toys which you have onboard, means that you're spending that much more time exploring the new areas you're in. Seeing more sights, etc. as well as getting to know both your cruising neighbors, & the locals.
For me, those are big perks vs. leaving behind 50lbs of novels, videos, & food which I can buy locally.

But consider this. The guys who race RTW do so with 1 (each); sleeping bag, pot, plate, spoon, & change of underwear. And on a crewed racing boat, if the wind's forecast to be light for a day/short race, crew will be left on the dock.... Be the boat a Maxi, or a 30'er. BTDT

[tp12]

Thank you everyone, I appreciate your help.

The Wanted: boat I've listed is definitely my dream boat but is looking more and more like my money no object boat. The maintenance costs of a 50' cat are putting me off so I'm looking at smaller designs. The limiting factor appears to be payload on the performance oriented designs I'm interested in which has lead me to starting this thread. I'm a big fan of the small boat on long, skinny hulls concept.

I think I have an appreciation of the difference between the various weights listed for each design but if you assume for all the boats they're built to design weight then payload is the relevant metric for what I'm looking for. The point about what each designer considers payload and not is a good point and I guess I'll have to have a chat to Schionning.

2t of gear for a couple and a toddler .. it's these kinds of numbers that will help me get an understanding of what people actually carry.

Once I've got a better idea of what I'd likely be carrying I can narrow down design choices. It's great to have so many designers and designs available but still a shame you can no longer build an Oram. I think they'd really come into the reckoning.

[Boatguy30]

For example, my boat has a fairly high displacement at almost 11,000 lbs but the hulls are very fine but deep. So as you haul the gear aboard, the waterline sinks fast. Overall the payload is excellent for a 34' multi, but you do still need to be careful. I have also never been to full load waterline even with full tanks 140 gallons of water. Probably still had 500 kg or more to go, but the speed/ performance drop of the last 500 kg prior to that is very noticeable.

Of course most people just raise the bottom paint.

[tp12]

Originally Posted by UNCIVILIZED

Yeah, I was just going to make the above comment myself. It's really not tough to calculate/take a SWAG @ one's waterplane cross section, & then figure your immersion rate.

Also, the full stipping out of the boat is SOP for any races of significance. And for heavily campaigned boats, it's done after each day's sailing or practice.
When you first start doing it, you find all kinds of crap on the boat, which you wonder why it was even there to begin with.

On the weight of gear thing, I can see the 1T per person, on a bigger boat. Assuming you carry a full load of chain & several sets of full sized ground tackle. Lots of H2O, fuel, food, & toys, etc.

Though, there is a flipside to such... the less entertainment type of equipment & toys which you have onboard, means that you're spending that much more time exploring the new areas you're in. Seeing more sights, etc. as well as getting to know both your cruising neighbors, & the locals.
For me, those are big perks vs. leaving behind 50lbs of novels, videos, & food which I can buy locally.

But consider this. The guys who race RTW do so with 1 (each); sleeping bag, pot, plate, spoon, & change of underwear. And on a crewed racing boat, if the wind's forecast to be light for a day/short race, crew will be left on the dock.... Be the boat a Maxi, or a 30'er. BTDT

I did my time in the Army and there was a reason I got out ... the idea of roughing it like that really only extends to the Sydney to Hobart for me. Cruising is comfortable in my mind

I'm a diver so I'll be keen to get a compressor and two tanks. Two sups, dinghy, couple of surfboards, fishing rod/reels/net/crabpot. It's easy for me to calculate their weight though. I also like to cook so a decent galley, fridge/freezer space, equipment is a must but I think all of these things are achievable. I read on my tablet so there won't be loads of books around though I'll have a tv, hdd with movies and tv on it and probably my ps4. I see those as bad weather alternatives though and take your point about getting out and about and experiencing everything. That's a big part of why I want to do it so I don't imagine that having some toys on the boat will curb that.

[Boatguy30]

The main thing would be if buying a limited production or custom boat. You have it weighed prior to purchase. Most international racing systems are now using weight in the rating formula and you should be able to get an accurate weight near a major yachting center for about the sample cost as the survey.

So you can calculate the actual payload, not rely on the designers or builder numbers. This does of course assume the designer's designed waterline displacement is accurate.

[yeloya]

I'll make trhe long stroy short.. If you are opting for fast catamaran with slim hulls you should forget about:
-heavy, center console 20+ HP outboards
-plenty of gear , spare parts that many people like have on board. (most of them don't even know how to use..)
-diving gears, compressor, etc..


Even if the boat can carry all these, the performance will be heavily impacted. Beyond the weight, how this weight is distributed is also very important. Lot of gear, spare sails etc on the bow and the big heavy outboard on the aft is the recipy to hobby horsing, uncomfortable (if not dangereous) sailing in open sea.
Catana 's are the best compromises in this respect, they can carry a bit more weight without noticeble loss of performance.
One last note, the biggest benefit of such light and fast cats are on light winds an d on upwind. However, when it starts blowing 18-20 kts, the differenece in speed will be much less against a Helia or Orana..(I've tried both against a Outremer 51 in every wind condition) You should also figure out that beside the weight restrictions, you will get much less space..
Cheers
Yeloya

[Cottontop]

If you're going to cruise, get a cruising boat. If you're going to race, get a racing boat.

When you try to combine the two, you mostly end up with neither.

I know many cats are sold as "performance cruisers," but they give up a lot in comfort trying for performane (slender hulls with reduced living space, low headroom to reduce windage, unprotected helms, etc.), and when you load them up, the performance is lost.