Ebay bought neoprene dy suit, size question.

[SubMariner]

In my experience, there is very little "pinch" with squeeze with a neoprene suit compared to a trilam - which can have a very sharp "pinch" when squeezed. You can consequently dive comfortably with a LOT less air in a neoprene drysuit even with very thin undergarments.

As I mentioned previously, I've dove both neoprene & shell drysuits. And there was no way I would dive in a short sleeved t-shirt & shorts under ANY drysuit for the very reasons I have already mentioned. "Very little pinch" is still pinch; drysuit hickies are NOT fun.

Furthermore, while there is some inherent warmth in a full neoprene drysuit, it does compress at depth and you do lose some of that insulation. Yet another reason for wearing "something" under the suit.

Pax,