The requirements of a GPS to enable data collection with Sea-Bird Scientific's SatView software are:  1. NMEA 0183 Output  2. Serial connection  The SAS GPS option includes a prewired Garmin model GPS 17xHVS.  This model is designed for marine use, and connects to serial port on your computer. It can be mounted to a pole for the duration of the cruise.  A suitable hand held model, is the GPS 72H from Garmin and has both the NEMA output and a serial connection. A optional serial cable is required, and also a power cable, if running from an external power source is desired.