For our Alaskan cruise I packed up a German SAK and small PSK
minus matches all in our checked bags. When we were on the ship
I removed and carried the items with us on all shore excursions without any problem, it was still the USA.
I have been told and personal observation confirms it that items brought on ship in open bags might be confiscated and held to trip end IF however these same items are in a closed purse or zipped backpack they go right thru the detectors. The items are still seen but ship personal are not allowed to open personal bags. I would not stretch this to pack an axe, machete, or
firearm tho, liquor, pocket knifes and lighters/matches seem to be fine. Check the purser's office for a small give away sewing kit.
AND don't forget some type of water purification tablet or equipment, supplies to last at least half of your trip.
A shipboard bug CAN happen.