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
SEIUN MARU
MMSI 431103000
Not yet on Master's MateFlag
JPNLength
116 m
IMO
9177600
First reported
Jun 2026
Last reported
Jun 2026
AIS reports
4
Registered in Japan, SEIUN MARU is an 116-metre craft. On AIS she shows as MMSI 431103000, IMO 9177600. Add SEIUN MARU to the Master's Mate Safety Initiative Network — free to join, and the fleet keeps an eye out for each other.
Free forever · No credit card
Is SEIUN MARU 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
Last known position · Jun 4, 2026
Position
35.3950° N, 139.7117° E
Crossing the Sea of Japan? 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
The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put SEIUN MARU 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 SEIUN MARU and switch it all on
Free to join · nothing to install to start · cancel anytime
About SEIUN MARU
What kind of vessel is SEIUN MARU?
SEIUN MARU is a vessel flagged to Japan.
Where was SEIUN MARU last seen?
SEIUN MARU was last reported in the Sea of Japan in Jun 2026 on public AIS.
What is SEIUN MARU's MMSI?
SEIUN MARU's MMSI is 431103000. IMO 9177600.
How big is SEIUN MARU?
SEIUN MARU is about 116 m long.
Is SEIUN MARU on the Master's Mate Safety Initiative Network?
Not yet. If SEIUN MARU is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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