A wetsuit keeps your body warm by insulating the body heat with neoprene. When you are in the water the water inside the wetsuit will be trapped and heated by your body temperature. The neoprene will not let the warm water go through and keeps it in the wetsuit.
When you need to replace your wetsuit, look for a lot of holes, cuts, and tears, or if the seams are broken or cracked, as well as if the neoprene is overly stretched / thinner, or cracked from dryness. In each of these instances, the wetsuit is not functioning properly and is not keeping you warm in the water.
Why you should wear a wetsuit is a pretty easy question of course. You wear a wetsuit to stay warm in the water for a longer period. But there are many other reasons to wear a wetsuit in the water.
When buying a wetsuit you should always check a couple of things. You have the basics of course what thickness, different zipper styles, size, type of wetsuit and the inner lining. But next to those basics you check these other factors as well. So this is more an intermediate buying guide ;).
In general, you have 4 types of wetsuit entries and some of them have different names and variants. But the most common is the back zip, front zip (chest zip), and the zip-free (zipperless) wetsuits.
In general there are six different wetsuit types with many different names. But the most common are, full wetsuit, short arm steamer, long sleeve shorty, shorty, long john and short john. There are some variations between them like hooded or not hooded or longer and shorter legs and sleeves.
