Your friend shouldIrene:A friend of mine was having some trouble with her drysuit leaking. After some goading, she tried wearing a 1 ml instead of undergarments...just to see if it would keep her warmer (since she was getting kind of wet anyways).
After one dive, she switched back to her thermals....said while she was warmer in the leaky spot, the squeeze with the wetsuit compression was not worth it at all. And this was on a shallow dive.
- get the leak fixed in her dry suit
-seak advice on that rather than listening to someone who has never dove a dry suit