So they dont get the bends and the co2 levels in the body have time to equalize.
Scuba divers who surface too quickly after a deep dive are prone to decompression sickness.
Recreational divers usually don't go any deeper than 60ft. The recreational dive limit is 130ft.
Divers dive in the sea/water, not earth.
Diving boards
the board
Dive knives can be purchased from a number of websites. Examples include Knife Depot, Scuba, Leisure Pro, Divers Supply, Divers Direct and Divers Warehouse.
Skin divers are people who dive into the ocean without using special equipment, unlike Scuba divers.
Slowly
Gravity.
People who dive are usually just referred to as divers. You can break them up into roughly four categories:Skin divers - who hold their breath, and do not use scuba equipment. Also sometimes called free divers.Sport divers - who dive for fun (they used to be called 'recreational divers', but now this term is used to distinguish sport divers from 'technical divers' who also dive for fun, but dive outside of WRSTC 'recreational' limits).Commercial divers - who dive for their jobs. By convention, this excludes recreational diving instructors, to differentiate from commercial divers who use equipment underwater, engage in saturation diving and use of elaborate gas mixes.Military divers - who form a sub-set of the navy.Not all divers fit neatly into these categories (police divers, rescue divers, fisherman who dive for their catch), but those tend to be the broad categories used.
To use it in that form, you could use it as a command. For instance, Dive into the water. To use it in another way, you would have to change the verb tense to "dove" or "diving" or something else like that.
If you mean "Ho deep can people DIVE", the limit for commercial divers is between 100 and 200 meters. There have been, however, experiments with people in pressure chambers, simulating VERY deep dives. They exceeded 600 meters.