VHF radio choices
Given the size of your boat and the lack of charging ability I would go with a hand held VHF. The new Standards are waterproof and use AA batteries which are easy enough to replace or to carry spares for. If you want or need in an emergency extended range you could install a VHF antenna on your mast and have the proper fitting available to connect to your handheld since most of their antennas are removeable. It is not true that a fixed mounted VHF is a maintainence problem. Any quality VHF, ie ICOM, Standard or Raytheon, should last for years with minimum requirements. As far as current drain that is also minimal and only when in the transmit stage, when in the receive mode you are drawing only miliamps--you can also operate most units using only five watts. Remember VHF is line of sight, accounting for the curvature of the earth and the height of your antenna maximum coverage would be around 20-30 miles with some exceptions. Find yourself a back issue of Practical Sailor where they review the various handhelds and go from there.