The following items are offered as an example of a list of first aid supplies which can be modified according to your needs and experience. This is a section taken from 'Divemaster's Quick Accident Response' and is the first of a series from that web site.

    Gloves
    Deodorant cleansing soap (antibacterial)
    Household Vinegar solution (neutralize jellyfish stings)
    Household ammonia
    Antibiotic Ointment
    Cortisone Cream 1%
    Non-aspirin pain reliever
    Hot packs
    Cold packs (pain relief)
    Denatured alcohol, 12 oz. bottle (sterilizing instruments)
    Telfa pads or plastic wrap (cover burns)
    Absorbent dressings (control severe bleeding with pressure)
    Squeeze bottle of water, 6 oz. (irrigating eyes and wounds)
    Squeeze bottle of sterile saline
    Sterile cotton, gauze pads, and adhesive tape
    Band-Aids and butterfly bandages
    Q-Tips
    Tongue depressors
    Disposable cups
    Razor blades, single edged
    Shaving cream
    Tweezers or forceps
    Needle nosed pliers with wire cutters (to remove fishhooks)
    Bandage scissors
    Lighter or waterproof matches
    Space blankets
    Backboard, splints and neckbrace, if space permits
    Penlight
    Seasickness medication
    Pocket mask (eliminates direct contact while resuscitating a

    person)

    For purposes of hospital and insurance follow-up and to avoid any legal problems, it would be a good idea to record as many of the events as possible during an episode. A pen and small notebook would be good to have in this respect.

None of these items will be of any use at all if there's no one on the boat who knows how to administer first aid. All divemasters and instructors should be fully certified in First Aid and their certification should be up-dated at least yearly.