Buying A Wetsuit - Wet suit Basics:

Wet suits come in a variety of configurations and materials. Some are designed specifically for diving and some are  more for surface water sports like waterskiing, surfing, wakeboarding, etc. Short sleeves and short legged farmer johns usually indicate a surface sports suit. There can be differences in the quality of the neoprene material used that make surface suits unsuited for diving applications.Do a search for wet suits on ebay and you'll get a couple of thousand results. The question is how do you find the wet suit that will work best for you?

As with any ebay item, do your research and know what you are buying before you start bidding.

For diving wetsuits you will see two basic styles, 1 piece and 2 piece suits. The 2 piece suits consist of a shorty (the top) and a farmer john / or jane (the bottom). A properly fitted 2 piece sill generally be warmer than 1 piece of the same thickness because of the double layer of neoprene over the core of the body. Having two pieces allows you to adjust your insulation for varying water temperatures whereas a 1 piece is what it is. Remember, water conducts heat roughly 25 faster than air. You need to minimize water flow in and out of the suit. Good fitting cuffs and neck are a big help in keeping you warm.

What are you buying it for?

Wetsuits really serve two purposes. Environmental protection, from barnacles, jelly fish, etc. and thermal protection. If you are buying just for environmental protection then fit is as critical an issue. One the other hand, if you are looking for thermal protection, regardless of where you buy them and for whatever neoprene thickness and configuration (one or two piece) the first and most important criteria is fit. It doesn't matter if the suit is 10 years old or straight from the manufacturer, if it doesn't fit properly it will not keep you warm and is not worth the money you payed for.

Wetsuit Thickness:

One big question to be answered when purchasing a wetsuit is the thickness of the neoprene. The only way to determine what thickness you need is to spend some time in the water with different thicknesses to determine your comfort level in the different thicknesses of suit in various water temperatures. After years of diving I have found I prefer many layers of thinner material, usually 3mm, rather than 1 layer of a thick suit. For me there is less of a Michelin Man effect with the thinner layers and it doesn't seem to create the same magnitude of increase buoyancy that a thick suit creates.

Fitting a Wetsuit:

As a general rule a good fitting wetsuit, regardless of thickness, will be warmer than a poor fitting one. A wetsuit should fit snuggly over the entire body but not so snuggly that it restricts movement or breathing.

You can't always rely on the size designations from the manufacturer. I've owned and currently use several wetsuits from different manufacturers and wear anything from a large to a XXL, depending on the suit. The best thing you can do to determine fit is to get measurements of the actual person this wetsuit fits from the seller. Here are the measurements you want.

Neck
Shoulders
Chest
Wrist to wrist, arms extended
Waist
Hips
Thigh (at the widest point)
Calf (at the widest point)
Ankle to top of shoulder
Inseam, ankle to crotch
Hip to ankle
Base of neck in back around crotch to V in front of throat

If you can get these measurements from the seller it is almost like getting fitted for a custom suit.

Obviously, the best way to determine fit is by trying the wetsuit on before you buy. That is just not possible on ebay most of the time so set your buying price accordingly.

What About A Dry Suit?

Dry suits have there place, really cold water or long emersion times but they require additional training to use them safely. If you get one do yourself a favor and get the proper training before taking it in open water.

Other Ways of Staying Warm:

Don't forget a hood, good booties and gloves. Your head is the biggest radiator on your body. Cover it and you'll stay considerably warmer. Rather than just a hood, consider a hooded vest. This adds one more layer of neoprene over the core of the body and makes a very good neck seal to keep new cold water out of the suit during a dive.

My Current Wetsuit of Choice:

The Henderson Hyperstretch, the material is much more flexible than other wetsuit neoprenes and they seem warmer in general, probably due to a tighter fit.