Maximum Passenger Weight

[keller34]

We bought a 2003 Ski Supreme V230SP (23ft) used. There is no owners manual and for the first time I have a concern with passenger weight. The seller said it had an 11 person limit (we will have 9 today, two of which are 6 and 7 yrs and weigh about 50lbs each) but I know there is a weight limit too and one of our passengers today is over 300lbs so I am concerned. Anyone know how to calculate number of passengers to weight of passengers? Or know where to find an owners manual? The Ski Supreme site only gives newer model info.
Additionally wondering if the weight limits include a full tank of gas already?

Would love to hear your thoughts.

Thanks!

 

[TANSL]

Determining the maximum number of passengers permitted on board means having to perform many calculations to make sure the stability and freeboard, fully loaded, are suitable.
From my experience I can assure you that such vessels often do not get permission for more than 6 passengers (total 450 kg).
The weight includes all fully loaded weights on board, including fuel, water, snacks, snorkelling, skies ... and the captain's cap. European legislation requires to even consider a margin for possible future additions of weight

 

[CDBarry]

You can check 46 CFR SubChapter T (180 something) or 46 CFR 170 for passenger heel and do the test. (www.gpo.gov has free access to the CFRs).

It would also be wise to contact a naval architect for a bit of a consult. Waller Marine is one firm in Texas that does this kind of thing.

 

[Ad Hoc]

If the specs say 11 persons, then it would be assumed to be using an international standard for the weight per person.

Currently the international standard is 75kg (165lbs), although this is currently being reviewed to be updated to 85kg, but that would not apply to your vessel.

So at 75kg x 11 = 825kg or 1820lbs. So that should be your rough objective of a maximum weight of 11 passengers to be around 825kg or 1820lbs total.

 

[TANSL]

It is not easy that ship meets any rule that permits 11 people on board but, besides that, I wonder, where will they be stored ?.
It has introduced the term "passenger". Does 11 passengers mean that the boat can carry 11 persons + crew?

 

[PAR]

The Ski Supreme V230SP may be rated at 11 persons (something I seriously question), but you'd have to be all but nuts, to take this many out in this boat. Hell 9, including a couple of kids is still way too many for a 23' wake/bow rider. Weight calculations would typically be arranged around an average of 180 pounds per, so carrying about a ton of live ballast seems just way over the top for this boat. The spec's for this boat do suggest "seating capacity", but damn with eleven 180 pounders aboard, there's literally no place to move and God help the crew, if everyone decides to move to one rail to see something.

Is this the Crusader I/O setup or the shaft and rudder version?

 

[DCockey]

The boat is a 23' ski/wakeboard boat. Assuming it is used in the US for personal recreation there are no Federal regulations directly affecting how many passengers can be carried. Federal capacity and buoyancy standards for recreational boats apply only to boats under 20' in length.

Ski Supreme boat's website lists "Seating capacity" in the listings of their current boats. That may just represent the number of people who are supposed to be able to sit in a seat at the same time, and may not be related to any considerations of occupant weight, buoyancy, freeboard, stability, etc.

 

[DCockey]

If the specs say 11 persons, then it would be assumed to be using an international standard for the weight per person.

......

That would seem to be a reasonable assumptions, but as I noted above the "11 passengers" for the OP's boat may refer to the number of seating positions and not have anything to do with passenger weight.

 

[DCockey]

Determining the maximum number of passengers permitted on board means having to perform many calculations to make sure the stability and freeboard, fully loaded, are suitable.
From my experience I can assure you that such vessels often do not get permission for more than 6 passengers (total 450 kg).
The weight includes all fully loaded weights on board, including fuel, water, snacks, snorkelling, skies ... and the captain's cap. European legislation requires to even consider a margin for possible future additions of weight

No calculations are required for US recreational boats over 20' in length.

 

[Ad Hoc]

That would seem to be a reasonable assumptions, but as I noted above the "11 passengers" for the OP's boat may refer to the number of seating positions and not have anything to do with passenger weight.

It shouldn't matter. If a number of "passengers" are noted in the spec of any boat, it assumes a deadweight. Since the performance of any boat is under a known set repeatable condition...part of said condition is the number of persons on-board = weight.

 

[DCockey]

It shouldn't matter. If a number of "passengers" are noted in the spec of any boat, it assumes a deadweight. Since the performance of any boat is under a known set repeatable condition...part of said condition is the number of persons on-board = weight.

The specs for current Ski Supreme boats do not use the word "passengers", just a number after "Seating capacity". Even if they did there are no legal rules, regulations or similar for recreational boats over 20' in length in the US which require any weight assumptions for passengers. Also, performance specs for such boats may be stated without anything said about the number of persons onboard.

This may be fundamentally different than for the types of vessels you design and the countries where they are used.

 

[Ad Hoc]

David

With respect you're missing the point.

A boats speed is related to several factors. The first being at what displacement? The displacement is lightship + deadweight = trials or full load displacement. At THIS displacement and with the engines installed the vessel shall achieve a certain speed.

From this the deadweight can be broken down into fuel, water etc etc...and also passengers. Passengers = weight, which makes up part of the total deadweight which goes back to the trails condition.

Thus if one takes away all the consumables what is left..a weight of "something". That someone = number of passengers. A nominal weight of a perosn,a nd this is the only "legal" aspect about this is 75kg. No other laws/regulations are needed regarless where the vessel is or what type.

Otherwise for a boat manufacturer to state 11 seats and the weight of those passengers if on-board during a speed run does not make the claim speed...it is a blatant lie and misrepresentation. Upon which the boat manufacture may say...well...we accounted for 11 children not adults, or something like that.

If there are 11 seats, then it means only one thing 11 person may be seated. If the performance of the vessel, speed, and/or stability is not possible, then it can become "legal" as it is a false claim of both.

Either the boat can carry 11 persons or it cannot. It is that simple...

 

[SamSam]

However many you put on board, they are all your responsibility.

 

[Ad Hoc]

However many you put on board, they are all your responsibility.

Indeed.

That is precisely what keller34 is doing. S/he is being responsible enough to ask as s/he can see what is going on and that it may be a problem. Well done

 

[NavalSArtichoke]

The USCG recently raised the Assumed Average Weight Per Person (AAWPP) from 165 lbs. to 185 lbs. for inspected vessels in the wake of several recent fatal accidents involving commercial watercraft which sank because overloading had degraded their stability.

http://www.uscg.mil/hq/cg5/cg5212/aawpp.asp

For 11 people total on a boat, that's over 2000 pounds of people, exclusive of the weight of all the other gear on the boat.

This link for a review of a 2003 Ski Supreme 220 SP lists the seating capacity as 10.

http://www.waterskimag.com/ski-boats/2002/12/31/ski-supreme-2003-220-sp/