There are several types of exposure protection that you can wear as a scuba diver. Drysuits are used in cold water diving. Wetsuits come in various thicknesses depending on the water temperatures, and rash-guards are comfortable for warm water diving.
Hood, Gloves, Booties
These items are additional exposure protection that may be used in cold water diving, or in more extreme diving conditions such as in caves or wrecks.
A compass will tell you the direction of magnetic North. This is important when learning how to navigate a new dive site, and how to return back to a dive boat. Navigating with a compass underwater is a great skill for any diver; beginner or experienced.
A dive torch will brighten things up underwater. The light allows colors to pop out as we lose color quickly in the water. It is also made specifically for underwater use. Firstly, it is waterproof Secondly, it is very strong which causes it to heat up. This is why you should only use dive torches/lights underwater, and not on-land as they may overheat.
Dive Knife / Cutting Tool
A dive knife or cutting tool is a standard piece of equipment for divers. This is placed in a pocket, or somewhere that is easily accessible by both hands (sometimes it it strapped onto your leg). It is especially useful for removing fishnets or lines that may cause entanglement to the diver.
Surface Marker Buoy or Dive Flag
This is a visible marker that floats on the surface while a diver is under the water. A delayed surface marker buoy (dSMB) is inflated and deployed near the end of the dive, during a safety stop before the diver comes up from the dive. While a dive flag will remain on the surface during the whole dive. Buoys and flags warn boat traffic and people above that there is a diver below and to exercise caution when moving on the surface.
Whistle / Noise-Maker
Another safety piece of any scuba diving kit is some sort of noise-maker, such as a whistle or a shaker. This is used to alert boats on the surface, or other people underwater, in the event of an emergency or a separation. Losing a dive on the surface is rare, but it can happen.