Instead of having a radio this is what I use on my boat, install a Fusion amp to any speaker and buy 3.5mm jack and hook to your smart phone..no need to have radio anymore.
http://www.westmarine.com/buy/fusion...4HIhoC5zvw_wcB
and this cable
http://www.cnaweb.com/6-2-rca-jacks-...yBQRoCByLw_wcB