1968 Selmer Series 9 B-flat and A clarinets
1962 Buesher "Aristocrat" tenor saxophone
Piper One Design 24, Hull #35; "Alpha"
I got the Garmin "GPS18 PC" (https://buy.garmin.com/shop/shop.do?cID=157 -- See "GPS 18 OEM"), for about $75. If you want waterproof, they have an external unit for about $108 ("GPS 17 HVS"). These put out RS232. This might be easier than duct-taping a handheld GPS to the cabin overhead.
I am feeding the GPS18 into my SR162 and it works well. The SR162 muxes the GPS into the AIS output RS232 NMEA. The Garmin unit ought to feed into a NASA AIS Radar, although I haven't tried it.