Nasa Marine Ltd. AIS radar, model , serial number N.S.S0910, version S0601-4525-8.35PL3, developer F.G. Everest. Purchased 11/05. Software upgraded 2007 to version T1028© 2006 (V0704.0-PICC18_9.50).

Upgraded software to B0301.3Fr PICC18_9.63PL4 5429 (2022).

The antenna is at the top of the mizzen mast. It's a Shakespeare 5215-C-X 36" whip, 3dB gain.

The unit is 6" x 4.5". I made some filters to cut down the display's brightness at night. The light has just an on and off setting. With it off at night, the button labels are not visible. I made three different filters for nightime use: a Roscolux #26 Medium Red, a 1.5 CTO, and a 2.0 OD neutral density. They're held on with 3/8" black Velcro.

AIS alarm that generates a "Ding-Dong" sound whenever a ship is within the alarm zone: