Thanks for all the advice! I am going to look into EMT shears, but, you are all right, there is no need for them.
Many of you have been saying to put them in my checked Cruise luggage, but I believe they would probably scan this luggage, because, afterall, your 'checked' luggage is not 'checked' in the sense that airplane luggage is.
-----on the notion of dining room knife, this concept makes a lot of sense. Swipe a steak knife, disembark with it, and throw it out before getting back on the boat. This poses two problems though. (1) Sheathing and general safety. My knives have secure sheaths. I just don't know how I would sheath a steak knife. (2) IF, on the off chance I was ever screened anywhere, a STEAK KNIFE from the DINING ROOM would NOT fly with any security personelle, while a diving instrument can be easily justified. 'sorry, officer. i stole this steak knife for scuba diving. i swear'. Ultimately, I don't think its worth the effort.
Just a question, how do you suggest I attach the EMT Shears? I feel my BC pocket would give them too much free range motion. I guess I could devise some bungie contraption.