es601:How many people have the oppurtunity to ck their weght with a new suit or equipment in saltwater at all times of the year before going away on a dive vacation? I know I don't.
Better make the time. If not before you go, then the first thing when you get there before starting your diving. If you initially check it in fresh water then you know it's going to leave you a shade on the light side. Being too light or too heavy can be dangerous. Just don't do it. You'd be better off not diving if you don't have time to see to the important stuff.