MMSI 367708970 · Call sign WDI5478
Not yet on Master's MateW.J. SIMPSON is an American work boat — 15.4 metres overall. She has a 6.1-metre beam and a draft measuring 1.4 metres. She broadcasts as MMSI 367708970, call sign WDI5478. Working vessels like W.J. SIMPSON are never truly alone on the Master's Mate Safety Initiative Network — free, with a fleet on watch.
Engine & systems telemetry, live AIS, weather and distress alerting for the vessels that earn their keep.
Rig her out — free →Takes 60 seconds · Your data stays yours · Built by cruisers, for cruisers
Joining the Safety Initiative Network doesn't just put W.J. SIMPSON on the map. It hands you the full bridge:
© 2026 Master’s Mate. All rights reserved.