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.
Recreational
SLOOP JOHN B
MMSI 368375270 · Call sign WDP6730
Not yet on Master's MateType
Recreational
Flag
USALength
9.4 m
Beam
3.2 m
Draft
2.4 m
Call sign
WDP6730
Official No.
1110731
First reported
Jun 2026
Last reported
Jun 2026
AIS reports
10
SLOOP JOHN B is an American family boat, 9.4 metres from stem to stern. SLOOP JOHN B has a beam measuring 3.2 metres and a 2.4-metre draft. She's on record as MMSI 368375270, call sign WDP6730. SLOOP JOHN B is exactly the kind of boat the Master's Mate Safety Initiative Network was built for — free, simple, and always on watch.
Free forever · No credit card · for recreational captains
Keep SLOOP JOHN B looked after — even when you’re not aboard.
Anchor alarms that wake you, a live camera at the dock, and weather you can trust before every run.
Look after her — claim free →Takes 60 seconds · Your data stays yours · Built by cruisers, for cruisers
Last known position · Jun 2, 2026
Position
42.5039° N, 70.8462° W
Cruising the Gulf of Maine? 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 recreational captains
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.
Onboard Cameras
Watch your boat from anywhere — live feeds and 24h recording, straight from your gateway.
Weather & Routing
GRIB wind, swell & current on the chart. Plan passages with ETA-calibrated forecasts per leg.
Worldwide Charts
Navionics-grade vector charts, satellite & raster overlays, online or off. Your whole cruising ground.
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.
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
Free to join · nothing to install to start · cancel anytime
About SLOOP JOHN B
What kind of vessel is SLOOP JOHN B?
SLOOP JOHN B is a Recreational flagged to United States of America.
Where was SLOOP JOHN B last seen?
SLOOP JOHN B was last reported in the Gulf of Maine in Jun 2026 on public AIS.
What is SLOOP JOHN B's MMSI?
SLOOP JOHN B's MMSI is 368375270. Call sign WDP6730.
How big is SLOOP JOHN B?
SLOOP JOHN B is about 9.4 m long, 3.2 m on the beam, drawing 2.4 m.
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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