Wet. dry suit are great for surfing for a few hours, but not for exposure for great periods of time.
aa3jy is right putting on on and hurrying is not gonna work. Take it from an old surfer.
I think you need to look at terminology a bit, dry suits are made to be worn with under clothes and they provide the warmth, the "dry suit" provides the barrier to the water, thus keeping you dry. Wet suits are the neoprene ones in 2-10mm thickness that count on the body and the neoprene to keep the water between the two "warm". Even the good ones will only keep you "relatively" warm. 7mm wet in 55-75 degree water will become quite cold in a matter of hours, and you will perish if not removed from the water in due time. Some folks will pump hot water in to the space between the skin and the wet suit (ala bering sea gold style)
a good dry suit with correct clothes under will keep you dry and warm, thus alive - MUCH longer than a wet suit. I have done full days of diving with a dry suit and never gotten cold. And only my head wet. Or suffered chills and such after a long day diving. Pee breaks can be a challenge or using the P-valve, especially for the female amongst us.
And when used correctly, dry suits can allow pretty good movement and activity. Gumby suits are for survival use only, very restricted movement, walking and such is nigh impossible for any length of time. However, IF you can get in it before you hit the water, you can gain several hours survival.
Getting in on dry pavement is a chore. Getting in, panicked, tossing deck, water or wet clothes, could take 10 minutes or so.