Sharkskin is virtually identical to lavacore. I use lavacore under my drysuit when diving in spring water that is 72f/22.2c. It won't be enough for the water temps you'll be diving in.Hello all! Thanks for all of the comments, haven't been checking this site regularly. I'll be doing the PADI Dry Suit Specialty with the London School of Diving in mid-March and they said that we'll be going to Wraysbury Lake. They didn't say that they wouldn't provide any undergarments, they only said that I should bring some warm clothes, and that these clothes are going to get wet.
I was thinking of using my Sharkskin Chillproof wet suit under the dry suit, it has an initial layer of fleece and wicks moisture away. Is that still not recommended?
I suspect that the school is going to provide undergarments and the clothes are just something light to be worn under the undergarments. You should definitely call them and ask before you go.