| Many types of underwater features make an | | | | close to the sediments on the seabed can result in the |
| interesting dive site, for example:* Wildlife at the site. | | | | particles being kicked up by the divers fins.* |
| Popular examples are coral, sponges, fish, sting rays, | | | | Temperature. Warm water diving is comfortable and |
| molluscs, cetaceans, seals, sharks, and crustaceans.* | | | | convenient. Although cold water is uncomfortable and |
| The Topography of the site. Coral reefs, drop offs | | | | can cause hypothermia it can be interesting because |
| (underwater cliffs), rock reefs, gullies and caves can | | | | different species of underwater life thrive in cold |
| be spectacular. Deep dive sites mean divers must | | | | conditions. Cold water means divers tend to prefer |
| reduce the time they spend because more gas is | | | | Dry suits with inner thermal clothing which offer greater |
| breathed at depth and decompression sickness risks | | | | thermal protection although require training and |
| increase. Shallow regions can be investigated by | | | | experience to use properly.* Currents. Tidal currents |
| snorkeling.* Historical or cultural items at the site. Ship | | | | can transport nutrients to underwater wildlife increasing |
| wrecks and sunken aircraft, apart from their historical | | | | the variety and density of that life at the site. Currents |
| value, form artificial habitats for marine fauna making | | | | can also be dangerous to divers as they can result in |
| them attractive dive sites.* Underwater visbility varies | | | | the diver being swept away from his or her surface |
| widely. Poor visibility is caused by particles in the water, | | | | support. Tidal currents that meet solid underwater |
| such as mud, sand and sewage. Dive sites that are | | | | vertical surfaces can cause strong up or down |
| close to sources of these particles, such as human | | | | currents that are dangerous because they may cause |
| settlements and river estuaries, are more prone to | | | | the diver to lose buoyancy control risking barotrauma. |
| poor visibility. Currents can stir up the particles. Diving | | | | |