Master's MateSafety Initiative Network
The Master's Mate Safety Initiative Network (MMSIn) — like AAA for the ocean, but free & community-driven. Cruisers keeping each other safe: anchor-drag & distress alerts, a verified captains directory, and a watch network that has your back.
Towing Vessel
BIG J.O.
MMSI 367618990 · Call sign WDH4558
Not yet on Master's MateType
Towing Vessel
Flag
USALength
37.5 m
Beam
11.6 m
Draft
3.7 m
Call sign
WDH4558
Official No.
1252860
AIS reports
1
On the American registry, BIG J.O. is a 37.5-metre working vessel. Below, she has a beam of 11.6 m and a draft measuring 3.7 metres. Her papers read MMSI 367618990, call sign WDH4558. The Master's Mate Safety Initiative Network welcomes BIG J.O. — free to join, cruiser-run, and always on watch.
Free forever · No credit card · for working boats
Built for boats that work — like BIG J.O..
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
Wherever BIG J.O. roams, you're never out there alone.
Thousands of cruisers on the Master's Mate Network — ready to help the moment something goes wrong.
Free with your claim · for working boats
The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put BIG J.O. on the map. It hands you the full bridge:
Systems Monitoring
Batteries, bilge, tanks, Victron & NMEA 2000 telemetry — your whole boat on one dashboard.
Live AIS & Traffic
See every vessel around you in real time. Closest-approach warnings before they matter.
Weather & Routing
GRIB wind, swell & current on the chart. Plan passages with ETA-calibrated forecasts per leg.
Distress Mesh
Mayday & Pan-Pan that ripple out to nearby cruisers — a watch network that has your back.
Anchor Watch
GPS-precise drag alarms that actually wake you — and your whole crew. Sleep through the night.
Worldwide Charts
Navionics-grade vector charts, satellite & raster overlays, online or off. Your whole cruising ground.
Onboard Cameras
Watch your boat from anywhere — live feeds and 24h recording, straight from your gateway.
Hail Any Captain
A verified captains directory + direct hailing. Reach the boat next to you, or across the bay.
Claim BIG J.O. and switch it all on
Free to join · nothing to install to start · cancel anytime
About BIG J.O.
What kind of vessel is BIG J.O.?
BIG J.O. is a Towing Vessel flagged to United States of America.
What is BIG J.O.'s MMSI?
BIG J.O.'s MMSI is 367618990. Call sign WDH4558.
How big is BIG J.O.?
BIG J.O. is about 37.5 m long, 11.6 m on the beam, drawing 3.7 m.
Is BIG J.O. on the Master's Mate Safety Initiative Network?
Not yet. If BIG J.O. is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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