A drysuit is waterproof suit worn by SCUBA divers to provide
exposure protection while in the water (other water sports also have drysuits but they are much simpler than those used for SCUBA). While there are many types
of drysuits available, they all have several features in common: they
all have various water tight seals over the openings, have valves
for allowing compressed air into the suit and alowing the air to
escape and they all have waterproof zippers.
Most drysuits have neck and wrist seals. A few suits have ankle
seals while others use attached boots or socks. Some suits do away
with the wrist seals in favor of dry gloves which usually snap into
place using some sort of locking mechanism.
The drysuit seals are made up of either latex or neoprene.
Many divers find the neoprene to be more comfortable but they tend to
allow water to leak into the suit. Latex seals are the most common
type. Regardless of the type of seal, they must be replaced after a
The drysuit itself can be made up of any number of materials but
they generally come in two types, shell suits and neoprene suits.
Shell suits are typically made from a trilaminate (butyl
rubber laminated on both sides by nylon), a bilaminate (butyl
rubber and nylon), Cordura, vulcanized rubber or DUI's CF200
fabric (a patented material made by Diving
All shell suits have several features in common:
The laminates offer the advantages of being quick drying, light
and easy to repair but are the more fragile of the various materials.
Vulcanized rubber is also quick drying and
easy to repair but is quite heavy. It is often used in polluted
waters by commercial divers. Cordura
is a heavier material but quite tough. CF200 is also quite heavy
and slow drying but is possibly the most durable.
As shell suits don't offer any thermal protection, undergarments
must be worn under them. Popular materials are usually quick drying,
pull moisture away from the skin and provide insulation even when
wet. Thinsulate and Polartec fleece are the most common materials. By changing the undergarments
worn, the shell suit diver can adjust the thermal protection as
Shell suits are usually baggy as the most common materials don't
stretch. The CF200 material is a notable exception.
Neoprene suits are made of either foam neoprene (the same
material as wetsuits) or compressed
neoprene]. These suits are designed to provide some insulation
but compress at depth. They are stretchable so they allow a closer
fit than most shell suits.
The compressed neoprene suits are designed to be somewhat
compression resistant but do not have the
inherent insulation of the foam neoprene suits and are usually worn
with undergarments. The fact that these suits are compressible
means that the diver's buoyancy
characteristics change with depth (the suit
becomes denser) forcing the diver to dive overweighted (if he is
five pounds negative at the surface, he may be 11 pounds negative at
90 feet). When the suit compresses, it also loses its insulating
properties. The main advantages of the neoprene suits is that if
they were to flood, the diver will still have some insulation from
the material itself. This is less of an issue with today's
synthetic fabrics that do a good job of keeping a diver warm even
when completely soaked. The other advantage
of the neoprene suits is usually cost.
The other difference between the various drysuit models is zipper
location. Since dry zippers are very expensive (the most expensive
component of the suit besides the suit itself), using the shortest
length that will allow the diver to don/doff the suit will reduce the
overall cost. The location favored for placing shorter zippers is
across the shoulder on the back of the suit. To don these
shoulder-entry suits, the diver steps in through the zipper, places
his arms in the suit and then pulls the remainder over his head. His
dive buddy then needs to zip him up. The other location for the dry
zipper is diagonally across the chest from
the shoulder to the hip. These suits allow the diver to zip himself
up but since the zipper is quite a bit longer, they cost
significantly more than than a comparable
Besides zipper location, there are many other drysuit options.
Many manufacturers offer two types of boots. The integrated boot
option involves a sole being attached to the bottom of the suit. The
disadvantage here is that the suit itself gets the wear and tear of
simply walking around on the beach/boat/rocks/etc. The other option
is a soft sock sewn onto the suit that is worn inside a
non-integrated boot. These boots often look quite like hiking boots.
Of course, a diver may find himself having left his boots at home and
not be able to dive (fins designed for boots are unwearable without
Another popular option for male divers is a overboard dump valve
aka pee valve. This is a tube that is attached to a condom catheter
that leads to the outside of the suit allowing a diver to urinate
during longer dives. This is considered an essential piece
of equipment for divers doing decompression dives (women divers are forced to wear dipers).
The other options include things like pockets, suspenders, knee,
butt and elbow pads and the list goes on. Buying a drysuit can be
like buying a car and is often the most expensive piece of equipment
a diver will purchase (and diving is a very expensive sport).