Here's an easy one (I think)

[LKunze]

I used a 7mm wetsuit for my first year of diving as well.  I thought it was alright at first.  Being new to diving at the time my buoyancy sucked and my air consumption was crap.  I stayed fairly warm partly because I was wasting so much energy with my subpar skills and generating more heat.  My first dive in Lake Superior in 42F water was a real rude awakening in the wetsuit.  Also, towards the end of the dive season in colder weather I was downright frigid.  I went with a drysuit the next year and haven't looked back.  I still get cold in my drysuit & 400G thinsulate undies sometimes particularly early and later in the season when there aren't any thermoclines to warm up in but it still beats a wetsuit though and it is so much nicer to get into and out of a drysuit.