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.
Cargo
SEISHO MARU
MMSI 431005903 · Call sign JD3766
Not yet on Master's MateType
Cargo
Flag
JPNLength
75 m
Beam
12 m
Draft
4.5 m
Call sign
JD3766
IMO
9790529
First reported
Jun 2026
Last reported
Jun 2026
AIS reports
2
SEISHO MARU is a cargo ship flagged in Japan, 75 metres in length. She carries a beam of 12 m and a 4.5 m draft. Her registration reads MMSI 431005903, call sign JD3766, IMO 9790529. SEISHO MARU is welcome on the Master's Mate Safety Initiative Network — free situational awareness and a watch network shared by vessels of every size.
Free forever · No credit card · for commercial operators
Eyes on SEISHO MARU, 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
Last known position · Jun 2, 2026
Position
34.9959° N, 138.4981° E
Transiting 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 · for commercial operators
The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put SEISHO MARU 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 SEISHO MARU and switch it all on
Free to join · nothing to install to start · cancel anytime
About SEISHO MARU
What kind of vessel is SEISHO MARU?
SEISHO MARU is a Cargo flagged to Japan.
Where was SEISHO MARU last seen?
SEISHO MARU was last reported in the Sea of Japan in Jun 2026 on public AIS.
What is SEISHO MARU's MMSI?
SEISHO MARU's MMSI is 431005903. Call sign JD3766. IMO 9790529.
How big is SEISHO MARU?
SEISHO MARU is about 75 m long, 12 m on the beam, drawing 4.5 m.
Is SEISHO MARU on the Master's Mate Safety Initiative Network?
Not yet. If SEISHO MARU is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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