Latex Swim CapsLatex caps are made of a thin layer of latex. They are easy to order customized, are very stretchable, and are probably the most popular type of swim cap.
Latex swim caps can last a long time with proper care. They do tend toward ripping if a swimmer leaves a metal hair clip in, has a metal part on a hair band, snags an ear ring, or has sharp fingernails and pokes one through the cap. I have some latex caps that are more than two years old ans till in good condition.
Latex caps are stretchy, so they fit most head sizes. They can "grab" long hair when being put on or taken off - and having your hair pulled is not comfortable. Once a swimmer is experienced at donning a swim cap, this is usually not a big problem. Latex swim caps are non-porous, so if it used in a warm environment they can increase a swimmer's body temperature as they trap a layer of warm water between the scalp and the cap, which results in insulating the swimmer's head from the cooling water of the swimming pool. One caution, some swimmers have an allergic reaction to latex.
Proper care for a latex cap is about the same as that of other types of caps. Rinse in cool water, air dry, and store out of the sun and in a place that won't get too hot (heat will break down the latex into a sticky mess). If a small dry towel is stuffed inside the cap, this can help the cap dry better and prevent the inside surfaces from adhering to each other. Some swimmers powder their caps with talc or baby powder, and while this does help the cap have a longer life, it also makes a mess and it makes the cap less adhering to the head; the cap tends to slip of of the swimmer more often.
Cheap compared to other materials. Compare Prices on Latex Swim Caps
I think latex caps are the most versatile and most used. They are relatively inexpensive, smooth and conforming enough to make good caps for races, and durable enough for training.
Silicone Swim CapsSilicone caps are the top of the line. They are super-stretchy, hypoallergenic, and tend to be more durable than other types of caps.
Silicone caps will last a long, long time with proper care. I have seen some caps - still used regularly - that are well over three years old. Like latex caps, silicone swim caps are subject to puncturing by sharp objects, but they are more resistant to that kind of damage compared to latex caps.
Swimmers I talk to like silicone caps. They are very conforming, but not in a tight, restrictive way, They don't pull hair the same way a latex cap can, and they are easier to put on, too.
Rinse, air dry, and store out of the sun, just like any other type of swim cap. Putting a small towel inside can help the cap dry faster.
Silicone swim cap prices are usually the higher than latex caps. Like other caps, you can usually find discounts if purchased in bulk. Compare Prices on Silicone Swim Caps
Silicone swim caps increase in popularity as the level of swimming meets increase. At the Summer Olympic Games, every swimmer probably wears a silicone swim cap, or wears a latex cap with a silicone cap over it. Since silicone tens to be very stretchy but also tends to want to hold its shape, it conforms and it smooths, making a better hydrodynamic swimming form out of a swimmer's head. Some silicone caps have special features to make them even more hydrodynamic.
Cloth, latex, or silicone. The swim cap you use (or don't use - if it is not against health regulations, you don't need to wear a cap if you don't want to) will help you go a little faster, or help you stay a little warmer, or help protect your hair form the pool chemicals and the sun.
Swim on!Swim Caps, Part I - Cloth/Fabric Swim Caps
Swim Caps, Part II - Silicone and Latex Swim Caps