Difference between diving and kayaking wetsuit

[vondo]

The neoprene may be different (less compressible for a diving suit) but in warm water like that it, a 4mm anything will be fine, maybe even warm. If I understand what the shirt you are talking about it, it looks like a fleece or something. That will not offer any warmth under water and I would not wear it.

The problem with a farmer john is it doesn't cover the arms/shoulders, so you would still want to layer it with a jacket or a shorty. Or not. Some of us would dive in those temperatures with no thermal protection.

 

[Crush]

For what it is worth, I have a farmer john (designed for paddling) that I use for scuba diving in warm water - it works just fine. The upper part of the farmer john is made of thinner neoprene than the legs are, and the cut-out around the neck and arms is generous - this all serves to make it good for paddling, but likely to let water in if you scuba dive with it as-is. The solution is to add a scuba wetsuit top, worn over the farmer john bottoms.