3mm vs 5mm?

[scubadada]

So I was pretty set on getting a 3mm full suit as I only plan to buy one suit right now. It will be for diving mostly the keys, FL east coast, and Florida gulf coast. I’ll occasionally hit a spring or two. I recently had a 3mm in 63 degree quarry and got cold towards the end but I usually run pretty hot so it wasn’t bad. Dive shop nearby recommended a 5mm and said I can always open it up and let water in and cool down, but if I have a 3 and get cold, can’t warm up. Anyone else think the 5 is the better option if trying to only get one? Thanks!

Hi @thomasj1107

I have been diving in SE Florida (Boynton Beach, Jupiter, West Palm) for 13 years. I have a full 3 mm, 5 mm, and 7 mm, as well as a 5/3 mm hooded vest, and use them all every year. I do not tolerate being cold as well as I did when I was younger. I will often do up to 4 dives per day, over 4 hours of dive time. Another important piece of equipment is a good boat coat, to protect you from the wind and cold during your surface interval. I wear gloves when it is cool, even if I don't need them for protection.

Personally, I wear my 3 mm +/- hooded vest down to mid-high 70s. I wear the 5 mm +/- hooded vest down to low 70s and the 7 mm with the hooded vest below that. With the 7 mm and hooded vest, I can do a couple of dives down to the low 50s, i.e. Southern California.

People sometimes joke that I am overdressed, I'm frequently the only warm diver on the boat.