I am afraid of the spread of piracy while boating, are the laws to carry a fire arm on a boat the same as on land?

First of all, most if not all of the pirate activity is taking place far form the United States, i.e. the Horn of Africa, and some shipping lanes in and around Indonesia. As long as you're boating near Washington State and Canada you should be okay.

The laws for carrying fire arms on boats should be the same as the laws applicable to the land to which the waters belong. However, if in the waters of one of the United States there may be federal maritime law that applies that would preempt any state law concerning the use of fire arms. Additionally, if you boat in international waters there may be international laws that apply to carrying fire arms on your boat.

Additionally, before you consider carrying a firearm on your boat check with your maritime insurance agent or the insurance policy. A firearm might be considered a hazardous material or hazardous instrument and void the policy, especially if your maritme insurance policy is for a pleasure boat.

NOTE: This answer is not intended to be legal advice and should not be construed in that way. This answer does not create an attorney-client relationship and no such relationship may be created absent a signed retainer agreement. The author is licensed in Illinois only, and his answer is for educational purposes alone.