geezus, 3600? was the bilge filled with water or something?
Take a 21' Eliminator, or a 21' Tahiti (see Jarvis' Tech sheet), or a 21' Bahner, for example- 1600 lbs, bare hull. 750Lbs for a BBC, Berkeley pump, 100 lbs.. 50 gals of fuel- 325 lbs, totals 2775 lbs... but weight, theres' more, about 1000 lbs of trailer, now your at 3775 lbs, EMPTY, Plus gear- cooler, chairs, umbrella, BBQ, etc. OH!, and if its a McMerCruiiser, add a couple hundred pounds more, 4K lbs is within reach. But hey, I have an F350 PSD, not a gas-stationwagon.
BTW- the 'bilge plug' gets used twice a year, in the fall, and in the spring...
Daniel