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.
Mobile Offshore Drilling Unit
PERCY JOHNS
U.S. Official No. 633949
Not yet on Master's MateType
Mobile Offshore Drilling Unit
Flag
USALength
54.9 m
Beam
53.3 m
Draft
7.4 m
First reported
Jun 2026
AIS reports
1
PERCY JOHNS, an American vessel, measures 54.9 metres on deck. She's built with a beam of 53.3 m and a 7.4-metre draft. She's on record as U.S. official number 633949. PERCY JOHNS is invited to the free Master's Mate Safety Initiative Network, where cruisers keep each other safe.
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Joining the Safety Initiative Network doesn't just put PERCY JOHNS 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 PERCY JOHNS and switch it all on
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About PERCY JOHNS
What kind of vessel is PERCY JOHNS?
PERCY JOHNS is a Mobile Offshore Drilling Unit flagged to United States of America.
What is PERCY JOHNS's U.S. Official No.?
PERCY JOHNS's U.S. Official No. is 633949.
How big is PERCY JOHNS?
PERCY JOHNS is about 54.9 m long, 53.3 m on the beam, drawing 7.4 m.
Is PERCY JOHNS on the Master's Mate Safety Initiative Network?
Not yet. If PERCY JOHNS is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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