Well according to the link given for the US regs we don't:
You do NOT need a commercial radio operator license to operate the following:
Coast stations operating on VHF frequencies with 250 watts or less of carrier power.
Ship stations operating only on VHF frequencies while sailing on domestic voyages (unless the vessel carries more than six passengers for hire, or the ship is larger than 300 gross tons and is required to carry a radio station for safety purposes).
Aircraft stations which operate only on VHF frequencies and do not make foreign flights.
As I'm not making a foreign flight then I don't need one.
