Oxygen should be an absolute necessity on a dive boat and would certainly be helpful on any boat. Knowledge is needed as the appropriate local emergency information number to call and this information should be readily available in the First Aid kit.. If the kit is used, it should be immediately replenished and should be up dated every 6 months to a year depending on the types of medications it contains.
Oxygen Resuscitation Equipment
The DAN Oxygen System provides an O2 cylinder in a case with appropriate pressure regulator, flow meter, tubing, airways and ventilation devices. Other oxygen sources are available-but the important thing is that the equipment should be up-to-date, readily available and someone should know how to use it properly.
Oxygen is the one first aid treatment that can be used with the full knowledge that it can only help and usually is the one treatment that will turn a serious diving injury around. It is the first thing you should think of in all serious decompression illness and should be used even if you're uncertain of its need.
It probably would be a good idea to have a backup kit-since most dives are 40-60 minutes away from the shore and the O2 tanks hold generally only 20 minutes of oxygen. A larger O2 tank would solve this problem but in most boats the space is limited.
If possible, have your divemasters take a DAN oxygen course or at least have studied their oxygen manual.
DAN now offers 'Remo2', a partial rebreathing apparatus that prolongs the oxygen supply of the O2 bottle.