Hi AmysOnline,
1. Don't put anything on your luggage that identifies it as scuba gear.
2. If the ticketing agent asks if you have any scuba gear, say, "What's scuba?"
3. Invest in a good luggage lock.
4. Carry critical gear on board, such as your reg, prescription masks, etc., as well as one day's change of clothes & toiletries.
5. Take things you can discard/leave after use, like paperback books, old T-shirts & shorts, and motel/hotel soaps, shampoos & conditioners.
6. Make sure you bring an adequate supply of needed medications, as well as the brand names of those drugs in any foreign countries you are traveling to (I can help you with this).
7. Do not dive without a dive accident policy. If it's an expensive trip, a policy with trip cancellation/interruption coverage, like DAN Preferred, is wise.
8. Bring along basic first aid & save-a-dive kits.
9. With foreign travel, visit the CDC & State Department websites far enough in advance to insure you are prepared for possible disease exposure, have proper documentation & are aware of any travel advisories.
10. Use the buddy check before entering the water.
Best regards.
DocVikingo