royheath
04-01-2004, 05:42 AM
As a newcomer, I can't seem to mention the word 'displacement' without the doors to hell being opened. I'm interested in the WEIGHT of a trailer/sailer that gives its displacement as 1125lbs. On another line the ballast, which is a swing keel, is given as 375lbs. Question - what is the weight of the boat?
Displacement is the weight of your boat floating. Since you have a trailer boat, take it to a paving company, grain storage out fit, local scales at the land fill, etc. where ever you can have the boat and trailer weighed. Then launch the boat and weigh the trailer alone. Subtract the trailer weight from the gross weight and you have the weight of the boat.
You could try to contact the manufacture and get the shipping weight (which will be an empty boat, no fuel, water, etc.) You can then figure how much additional weight you have aboard by simple calculation of volume (tankage) or the carry on weight (sails, gear, cooler full of beer, crew, etc.) This will give you an idea of the weight (displacement) of your cruising trim (full up tanks, kicker hanging on transom, etc.) so you can tell if you are over or under your ideal waterline. All boats seem to have a sweet spot in regards to where they perform the best and this is usually based on it's target displacement. Some designs like to be light to do there best, others a little over the target displacement before they show their heels.
The boat most likely weighs 1125 as your ballast is 375, making the ballast to displacement ratio 33%, a reasonable number for a centerboard trailer boat.
Hope this VERY simplified explanation helps your needs . . .
