properly complete pre-dive checks include: not using a written checklist, the checklist being over-complicated, in too much detail or in an inconvenient order, time pressure peer pressure distractions and interruptions lack of space overconfidence and complacency, often influenced by outcome bias and combinations of these. Breaking pre-dive checks into groups which are done at different stages of preparation may require some of the checks to be repeated, but can still be more effective than doing everything at the last minute, when the conditions in which the checks are done are more conducive to attention, comfort and making any necessary adjustments to the equipment. This can apply particularly to diving from small boats, when assembly of the breathing set and partial kitting up in the diving suit before launch may be necessary due to space constraints and a wet bumpy ride to the site. Training, practice and experience To make effective use of standard procedures, the diving team must be competent in the procedures, particularly the diving and emergency skills. These skill sets are the basis of the standard operating procedures, and have themselves been standardised to a degree where they are largely internationally accepted, and are portable between organisations without requiring much re-learning. A large part of the variation is associated with different equipment and equipment configurations, and operators need to become familiar with new equipment under controlled conditions before using them in the field. This is the realm of formal training for diving certification, which is normally done by registered diving schools and instructors, and equipment rating and familiarisation, which may be done by the employer or by diver training schools, depending on the risks and complexity of the training, and how much unfamiliar equipment is involved. For example, basic operation of an unfamiliar mode of life support equipment like surface supplied diving or a rebreather is likely to be learned at a school, while the details of operating a different model of non-diving equipment, like a hydraulic bolt-tensioner is likely to be learned from a skilled operator of that equipment, or at a manufacturer's familiarisation workshop. It is common practice to record such training and the associated assessment in the diver's logbook, as well as any certificate which may be issued. Appropriate response to minor life-support equipment malfunctions which can be corrected by the diver is very important for diving safety. The diver is expected to deal with