Help me understand "dry boat" weight...

[Cookie Jar]

Good morning to all,

I am selling Cookie Jar and searching for another boat. Although It may seem obvious from the concept of "dry weight" itself, my issue is related to trailer-sailers and my question is "will I be able to pull it or not"... and that may be the "small" difference between pulling it myself or having to pay for transport, what would eventually render the deal useless due to costs.

So, does dry weight mean the complete boat (absolutely complete with everything from fittings to cushions, basic sail wardrobe and all else that come from factory) or only the hull itself with the absolute minimum "to float and sail"?

Thanking you in advance,
Cookie Jar

 

[Topcat47]

Dry weight typically refers to the weight of the factory supplied minimum sail-away package, less fluids (fuel and water). It usually does not include an allowance for electronics, fenders, life raft/sling, dinghy and associated outboard. It also excludes stuff like life jackets, foul weather gear, ordinary clothing, sleeping bags, food, etc. More worrying for the trailer sailor, it may also exclude anchor chain, other than a short length attached to some multiplait or a gas bottle to fuel the cooker. You'd be surprised how much all this weighs..

 

[Cookie Jar]

Hi Topcat47,

Thanks for the prompt reply.
Yes, it all adds up and quickly! That was my doubt because the boat I am looking at right now (a Shark 24) has a dry weight of 1T, give or take one kg... My trailer is rated for 1300kg but the trailer itself weighs 280kg, so it is virtually on the limit, giving me only a 20kg threshold...and over here in central EU, the road side police can be a real pain even if you have 1kg more.

I can definitely remove stuff from the boat and put it on the car, but I was wondering if I needed to remove more stuff from the boat or not (unfortunately I do not have a road side scale where I can test it), so I guess that removing all the "add ons", from stove to lifejackets and only leaving the basic of basics will make it work...

I hope...

 

[PuffTheMagicDragon]

Perhaps the class association will be able to provide accurate answers to whatever information you require.

 

[Sticky Fingers]

IIRC the weight of the trailer is counted towards the vehicle weight, not the towed weight. Your rated trailer weight ill be the load it can carry.

 

[lw395]

IIRC the weight of the trailer is counted towards the vehicle weight, not the towed weight. Your rated trailer weight ill be the load it can carry.

That does not seem to be the case in the UK.
Most newish trailers are plated with a max weight, which is trailer plus load. The car must be legal to tow the max weight.
The plate will also show the maximum load and probably the empty weight of the trailer.
AIUI, it's not technically legal to tow an empty trailer if its max loaded weight exceeds the car's limit.

May be different elsewhere of course.

Something like a farm trailer might be nominally a 'half ton trailer' to carry half a ton, but it will have a plate on it giving the tare.

In reply to the OP, the claimed dry weight of a design could be wildly wrong for a production boat. Nothing unusual in using 5% more resin in the hull, different fittings, optional extras.
Personally I would want a good margin for this, plus loose kit etc.

 

[oldharry]

IIRC the weight of the trailer is counted towards the vehicle weight, not the towed weight. Your rated trailer weight ill be the load it can carry.

No, Trailed weight is the all up weight of the trailer and its load. The trailer plate should indicate the maximum permissible load, to which the weight of the trailer is added to get the Trailed weight and the manufacturer of the towing vehicle will have set the maximum allowed. It doesnt necessarily solve the problem to pile all the heavy gear in the car to reduce the trailed weight. The towing vehicle will have a MAM figure specified - maxim allowable mass, which is the all up weight of the towing vehicle, its load, plus the trailer and its load. Down here on the S Coast Plod has regular campaigns to check private vehicles towing anything, caravans, boats or whatever. A worryingly high percentage of towed loads are found to have dangerous faults including insecure loads and overloading. BiL now retired was a French Gendarme. He warned me that they were very hot on overloaded cars and often stop and check a loaded GB car because they are often above the manufacturers limit.

Having said all that, I have been towing boats trailers and caravans large and small all my life, and have never yet been stopped....

 

[Tranona]

"dry weight" is not a term used in describing boat weights or displacement. I very much doubt your published weight has much connection with the actual weight. There is an ISO standard for calculating displacement but does no necessarily correspond with the weight of the boat as it leaves the factory.

The only way to determine the weight of the boat for towing purposes is to weigh it in the state you want to tow it. The weights you quoted are simply not reliable enough and your 1000kg boat is almost certainly far heavier than that. There may of course be ways of reducing the weight by transferring some loose things to the car, but you will only know once you have a reliable weight to start with.

 

[Sticky Fingers]

IIRC the weight of the trailer is counted towards the vehicle weight, not the towed weight. Your rated trailer weight ill be the load it can carry.

That does not seem to be the case in the UK.
Most newish trailers are plated with a max weight, which is trailer plus load. The car must be legal to tow the max weight. The plate will also show the maximum load and probably the empty weight of the trailer.
AIUI, it's not technically legal to tow an empty trailer if its max loaded weight exceeds the car's limit.

May be different elsewhere of course.

Something like a farm trailer might be nominally a 'half ton trailer' to carry half a ton, but it will have a plate on it giving the tare....

No, Trailed weight is the all up weight of the trailer and its load. The trailer plate should indicate the maximum permissible load, to which the weight of the trailer is added to get the Trailed weight and the manufacturer of the towing vehicle will have set the maximum allowed. It doesnt necessarily solve the problem to pile all the heavy gear in the car to reduce the trailed weight. The towing vehicle will have a MAM figure specified - maxim allowable mass, which is the all up weight of the towing vehicle, its load, plus the trailer and its load. ....

Ah OK I stand corrected. Apologies.

 

[Cookie Jar]

Thank you everyone for all your replies.

I guess I will have no choice other than class associations and model dedicated forums, but I am really surprised with the suggestion that the weight could be really far off the stated displacement from the manufacturer... A small difference will always be present in almost every article on the market with the exception of high precision parts, but to be far off really astonishes me. A 5 to 10%difference in 1Ton is not that much to make me look away (surely I can strip the boat out of 50kg), but much more than that makes it is unreasonable. And I even wonder why manufacturers even bothered in stating specs... Oh well... maybe only because they just had to state something.

I know exactly what my trailer weighs, how much load it can carry and I know what my car is able to (legally, of course) pull. My driving license is not an issue... but the boat is the apparent mystery weight and potential deal killer.

Thanks again everyone.

 

[Tranona]

As it is a one design would imagine that the build weight would be fairly consistent, indeed might well need to be accurate for a boat to be considered in class. So the Class Association will almost certainly have an accurate weight for a standard boat and other owners will know their trailing weight. However I note that Sailboatdata gives the weight as 998kgs and wikepedia 950kgs. The class rules may well have a mean weight and an allowable tolerance. So consulting the association seems the sensible thing to do given how critical it is for your situation.

 

[QBhoy]

A real mine field....

An example...
My trailer is a sbs 1600b. To the unaware, this might suggest it can take a 1600kg boat. It can't.
1600kg is the max gross weight, including the weight of the trailer. A closer look at the stamped plate tells me that the max load (boat) is 1300kg....suggesting the trailer is 300kg.
The next thing to think about is the vehicle you tow it with. It's a bit late for Google and this, but I'm sure the max gross train weight able will be stamped on the plate under the bonnet of the car.
There are other issues too.
For some, towing a 1750kg boat and trailer with a 1750kg car like a BMW 5 series is perfectly legal......
But if you tow the same boat and trailer with a more suitable and capable Land Rover discovery at 2600kgs.....it might be illegal ! Crazy.

 

[Cookie Jar]

Thanks you all for your replies.

I have contacted a few Shark 24 owners and although I could pull it, I could not have anything inside the boat - ever- when towing, so this actually means that on practical terms, I will not go down this route.

Thanks again to all !