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.
Tug
OHYAMA MARU
MMSI 431010701 · Call sign JD4284
Not yet on Master's MateType
Tug
Flag
JPNLength
40 m
Beam
12 m
Draft
3.8 m
Call sign
JD4284
First reported
Jun 2026
Last reported
Jun 2026
AIS reports
19
Registered in Japan, OHYAMA MARU is a 40-metre working tug. She carries a 12 m beam and a 3.8-metre draft. On AIS she shows as MMSI 431010701, call sign JD4284. OHYAMA MARU can join the Master's Mate Safety Initiative Network for free: think of it as a watch network that has every boat's back.
Free forever · No credit card · for working boats
Built for boats that work — like OHYAMA MARU.
Engine & systems telemetry, live AIS, weather and distress alerting for the vessels that earn their keep.
Rig her out — free →Takes 60 seconds · Your data stays yours · Built by cruisers, for cruisers
Last known position · Jun 3, 2026
Position
35.6400° N, 139.7627° E
Working 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 working boats
The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put OHYAMA MARU on the map. It hands you the full bridge:
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.
Weather & Routing
GRIB wind, swell & current on the chart. Plan passages with ETA-calibrated forecasts per leg.
Distress Mesh
Mayday & Pan-Pan that ripple out to nearby cruisers — a watch network that has your back.
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.
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 OHYAMA MARU and switch it all on
Free to join · nothing to install to start · cancel anytime
About OHYAMA MARU
What kind of vessel is OHYAMA MARU?
OHYAMA MARU is a Tug flagged to Japan.
Where was OHYAMA MARU last seen?
OHYAMA MARU was last reported in the Sea of Japan in Jun 2026 on public AIS.
What is OHYAMA MARU's MMSI?
OHYAMA MARU's MMSI is 431010701. Call sign JD4284.
How big is OHYAMA MARU?
OHYAMA MARU is about 40 m long, 12 m on the beam, drawing 3.8 m.
Is OHYAMA MARU on the Master's Mate Safety Initiative Network?
Not yet. If OHYAMA MARU is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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