I've heard guys that tried the cell phone antennas say they sucked and were a waste of money.
I have a new SH Quest radio and 8 ft Shakespeare galaxy antenna on my small cc and get great range. This galaxys outperformed digital antennas in a powerboat test. Also used a gold solderless connector by Shakespeare recommended by Dale on another board. He stated just changing this connector made a marginal performance to very good performance.
Off of block island I hear guys in the canyons sometimes, granted I can't transmit that far. Sounds like you just need new equipment and good connections. They have a fairly cheap device to check your equipment.
Panbo: The Marine Electronics Weblog: Shakespeare's ART-3, check your transmitting power!
For disaster time, losing electrical power, I have a floatable handheld with gps to call for help.