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.
Freight Ship
JOHN SHERWIN
U.S. Official No. 276445
Not yet on Master's MateType
Freight Ship
Flag
USALength
239.7 m
Beam
23.1 m
Draft
10 m
First reported
Jun 2026
AIS reports
1
JOHN SHERWIN, a merchant ship flagged in the United States, measures 239.7 metres on deck. Below, she has a beam of 23.1 m and a draft measuring 10 metres. On the registers she's U.S. official number 276445. Put JOHN SHERWIN on the Master's Mate Safety Initiative Network — free to claim, with a whole fleet watching out for her.
Free forever · No credit card · for commercial operators
Eyes on JOHN SHERWIN, around the clock.
Real-time AIS, full systems telemetry, distress alerting and worldwide charts — your hull on one dashboard, from anywhere.
Put her on the dashboard — free →Takes 60 seconds · Your data stays yours · Built by cruisers, for cruisers
Wherever JOHN SHERWIN 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 commercial operators
The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put JOHN SHERWIN on the map. It hands you the full bridge:
Live AIS & Traffic
See every vessel around you in real time. Closest-approach warnings before they matter.
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.
Worldwide Charts
Navionics-grade vector charts, satellite & raster overlays, online or off. Your whole cruising ground.
Weather & Routing
GRIB wind, swell & current on the chart. Plan passages with ETA-calibrated forecasts per leg.
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.
Hail Any Captain
A verified captains directory + direct hailing. Reach the boat next to you, or across the bay.
Claim JOHN SHERWIN and switch it all on
Free to join · nothing to install to start · cancel anytime
About JOHN SHERWIN
What kind of vessel is JOHN SHERWIN?
JOHN SHERWIN is a Freight Ship flagged to United States of America.
What is JOHN SHERWIN's U.S. Official No.?
JOHN SHERWIN's U.S. Official No. is 276445.
How big is JOHN SHERWIN?
JOHN SHERWIN is about 239.7 m long, 23.1 m on the beam, drawing 10 m.
Is JOHN SHERWIN on the Master's Mate Safety Initiative Network?
Not yet. If JOHN SHERWIN is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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