As a keen scuba
diver I've travelled with equivalents of everything on your list and the one that I consistently have problems with is pressure vessels. Yours will be worse as the CO2 cartridges will be pressurised with the valves in place. Scuba
cylinders, regardless of how small must be empty, with the valve removed, which you cannot do. I would be doing everything possible to avoid carrying those. If you can't, arrive at the airport
early, have documentation
with you and packed with the vests showing what they are and be prepared for a lot of questions.
Strangely, I very rarely have problems with batteries and some of mine are the size of a football.
Things to consider:
Airline staff do not like anything they do not recognise. Standard power tool batteries will have a much easier passage
than customised light, PLB etc batteries. Again, be prepared for a lot of concern over strange looking, sealed, pressurised CO2 tanks
. If your departure and arrival airports frequently see boating equipment
it may be of some help.
and airline staff may have different views on what is not allowed. Just because you made it past check-in does not mean all is going ok behind the scenes. Again, arrive early and allow plenty of time for answering questions.
Interpretations and attitudes vary wildly between different staff. A smile can work
miracles. Enforcement and issues can often be determined by whether the officials mood. Again smile and avoid being argumentative.
Have a backup plan should something not be accepted for transport.