How much does body weight effect swimming speed?

This has been something I've wondered the last few years. I used to be a college swimmer, fit and trim, but the 10 years since then I've drank my fair share of beer and ate plenty of cheeseburgers. Just curious what peoples' take is on how much the extra baggage really effects swim races. I don't really fit the swimmer mold anymore. I'm 31, 6'2", and 270lbs with a huge beer gut. I got some strange looks since the meet i was in recently was a USAS meet and I outweighed my competition by 100lbs in many cases. My first race in about 5 years i went 23.4 in the 50y free. I didn't expect to be that fast at this weight but at the same time I almost wonder if the added intertia is helping me more on the start and turns. Followed it up with a low 52 in the 100y free but I had a horrible reaction on the start and incorrect pacing. I think if i raced again today that'd be deep in the 51 range. For reference, typical non-taper times for me in college were in the low-mid 22 range at just a tick over 200lbs but I was obviously a lot stronger, younger, and doing a TON more yards at the time, that's why it makes me wonder just how much the weight is actually holding me back. How much time do you think I stand to drop if i were 50lbs lighter? Could it be a measurable difference or something just slight? I guess I ask that to see if it'd be worth my while to drop that much weight quickly by dieting in addition to the swimming i'm doing. I don't really like dieting, and i generally eat what I want, when i want. Not gorging myself at every meal doesn't really seem to fit into my lifestyle :blush: Anyone have a similar story? "I dropped XX lbs and went XX seconds faster because of it." Maybe it's an immeasurable, but I thought I'd ask for opinion anyway. I'm hoping it doesn't turn into a "to diet or not to diet" discussion though.