Padi safe diving practice is summed up as follows...to be a good, safe diver, you should...

Maintain good mental and physical fitness for diving. Keep proficient in diving skills, striving to increase them through continuing education and reviewing them in controlled conditions after a period of diving inactivity.

Be familiar with dive sites. If not, obtain a formal diving orientation from a knowledgeable, local source. If diving conditions are worse than those in which you are experienced, postpone diving or select an alternate site with better conditions. Engage only in diving activities consistent with your training and experience.

Use complete, well maintained, reliable equipment with which you are familiar; and inspect it for correct fit and function prior to each dive. Deny use of your equipment to non-certified divers. Always have a buoyancy control devise and submersible pressure guage when scuba diving. Recognise the desirability of an alternate air source and a low pressure buoyancy control inflation system.

Listen carefully to dive briefings and directions and respect the advice of those supervising your diving activities.

Adhere to the buddy system throughout every dive. Plan dives - including communications, procedures for reuniting in case of separation, and emergency procedures - with your buddy.

Be proficient in dive table useage. Make all dives no-decompression dives and allow a margin of safety. Have a means to monitor depth and time underwater. Limit maximum depth to your level of training and experience. Ascend at a rate of 60ft / 18m per minute.

Maintain proper buoyancy. Adjust weighting at the surface for neutral buoyancy with no air in your BCD. Maintain neutral buoyancy whilst underwater. Be buoyant for surface swimming and resting. Have weights clear for easy removal, and establish buoyancy when in distress while diving.

Breathe properly for diving. Never breath-hold or skip-breathe when breathing compressed air, and avoid excessive hyperventilation when breath-hold diving. Avoid overexertion whilst on the surface and underwater and dive within your limits.

Use a boat, float, or other surface support station whenever feasible.

Know and obey local diving laws and regulations, including fish-and-game laws and dive-flag laws.