Well you can’t take a dive knife on a cruise ship either :(
Returning from a day of diving in Greece we had to go thru their version of TSA, same line but agents with less humor and poorer English.
We were taken into a room, asked to unpack the dive bag and show them "any other weapons I had", a line cutter is okay! And BTW, Greek wrecks are covered with 2000 years of fishing lines and nets!
I repacked the divebag, was thrown into the back of a police car and driven out the long dock to the ship where the police showed ship security my "weapon". The Master-at-arms smiled, said yes he is a diver and handed me my knife back.
So if you want to avoid the long walk out the pier with the 50 pound divebag pack a knife but your results may vary.
Make sure everything you pack with batteries is turned off, maybe a little duct tape over the switches so they don’t overheat in your bag. Cannister style dive lights with those batteries and cable make TSA X-ray viewers very nervious :( You will get more personnel attention!