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.
Vessel
SLOOP JOHN B
MMSI 367458810 · Call sign WCZ9311
Not yet on Master's MateFlag
USACall sign
WCZ9311
Official No.
WN2027ND
First reported
Jun 2026
Last reported
Jun 2026
AIS reports
86
On the American registry, SLOOP JOHN B is a boat. She broadcasts as MMSI 367458810, call sign WCZ9311. SLOOP JOHN B can be part of the Master's Mate Safety Initiative Network at no cost — a community watch that never sleeps.
Free forever · No credit card
Is SLOOP JOHN B your boat?
Your free claim unlocks the most powerful cruising platform ever built — anchor watch, worldwide charts, live AIS, weather routing, and a network of cruisers watching each other’s backs.
Claim this boat — free →Takes 60 seconds · Your data stays yours · Built by cruisers, for cruisers
Live AIS position · Jun 9, 2026 12:36 UTC
Position
47.6397° N, 122.3405° W
Status
Under way (engine)
Speed
0.0 kn
Course
360°
Crossing the Salish Sea? You're never out there alone.
Thousands of cruisers on the Master's Mate Network — ready to help the moment something goes wrong.
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The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put SLOOP JOHN B on the map. It hands you the full bridge:
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.
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.
Onboard Cameras
Watch your boat from anywhere — live feeds and 24h recording, straight from your gateway.
Systems Monitoring
Batteries, bilge, tanks, Victron & NMEA 2000 telemetry — your whole boat on one dashboard.
Distress Mesh
Mayday & Pan-Pan that ripple out to nearby cruisers — a watch network that has your back.
Hail Any Captain
A verified captains directory + direct hailing. Reach the boat next to you, or across the bay.
Claim SLOOP JOHN B and switch it all on
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About SLOOP JOHN B
What kind of vessel is SLOOP JOHN B?
SLOOP JOHN B is a vessel flagged to United States of America.
Where was SLOOP JOHN B last seen?
SLOOP JOHN B was last reported in the Salish Sea in Jun 2026 on public AIS.
What is SLOOP JOHN B's MMSI?
SLOOP JOHN B's MMSI is 367458810. Call sign WCZ9311.
Is SLOOP JOHN B on the Master's Mate Safety Initiative Network?
Not yet. If SLOOP JOHN B is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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