Mace, pepper spray, and knives also are prohibited and may not be brought into Jamaica without specific authorization from the Jamaican Ministry of National Security.
This is from: http://travel.state.gov/content/pass...y/jamaica.html

Meanwhile, I always carry a tool (you might call it a 2.5in bladed instrument, a 'knife' or a wee cutlass) wherever I am, home and travel. When travelling it is the last thing to go in checked luggage and the first thing out. I carry it with the clip and short lanyard showing in my front pocket - not concealed - and have only had a problem with it once, in Curacao, but that is another story.