That’s an excellent question. In short, other than perhaps a thin rashguard, you don’t wear clothes under your wetsuit. It is, as the name implies a wet suit and anything you wear underneath it is going to get wet. I invite you to visit our website to read up on how thermal protection works. Here’s a link to the gear section: https://www.coldwatersafety.org/gear-guide. In a nutshell, the suit has to be snug-fitting in order to prevent cold water from flushing in and out. So if you want more insulation, you have to get a thicker suit. Thickness of neo = warmth. That gear section has a sub-section about troubleshooting. So if you stop paddling for a lunch break and you get chilled on the beach while wearing a wetsuit, you need to cut convective and evaporative heat loss and the sub-section tells you all about it.
Ha Ha! The old vasolene trick. Winter of 1984 my kayak partner and I spent our time in our new Nordkapps, practicing with our cold weather gear (thick wetsuits) full hoods etc. Water was 35-40F so pretty brutal. The face - holy crap that burned. Some guy tells us about vasolene. That was a comical bust. Slathered it on and it got everywhere, couldn’t keep a grip on the paddles with neo gloves. That one crashed and burned in a big hurry. One thing we found useful was priming the wetsuits with warm water so that we avoided that initial entry of cold water - because when that happened, people could hear us squealing about a mile away.
That’s a great report and analysis. We all make mistakes and I’m always appreciative of fellow paddlers who have the courtesy and courage to share their mishaps with the rest of the paddling community. It’s so much better to learn how to avoid stuff by reading about it than by direct personal experience.
Not geared up properly for 50° water. Especially for zero experience kayakers. Sad a kayak touring company would do that. Wetsuits are cheaper than drysuit is their motivation.