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
HIRONO MARU
MMSI 431013062 · Call sign JD4561
Not yet on Master's MateType
Tug
Flag
JPNLength
33 m
Beam
9 m
Draft
3.5 m
Call sign
JD4561
First reported
Jun 2026
Last reported
Jun 2026
AIS reports
25
Registered in Japan, HIRONO MARU is a 33-metre tug. She has a beam of 9 m and a draft measuring 3.5 metres. On AIS she appears as MMSI 431013062, call sign JD4561. Put HIRONO MARU on the free Master's Mate Safety Initiative Network and keep the working fleet looking out for each other.
Free forever · No credit card · for working boats
Built for boats that work — like HIRONO 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
37.2330° N, 141.0201° 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.
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The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put HIRONO 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 HIRONO MARU and switch it all on
Free to join · nothing to install to start · cancel anytime
About HIRONO MARU
What kind of vessel is HIRONO MARU?
HIRONO MARU is a Tug flagged to Japan.
Where was HIRONO MARU last seen?
HIRONO MARU was last reported in the Sea of Japan in Jun 2026 on public AIS.
What is HIRONO MARU's MMSI?
HIRONO MARU's MMSI is 431013062. Call sign JD4561.
How big is HIRONO MARU?
HIRONO MARU is about 33 m long, 9 m on the beam, drawing 3.5 m.
Is HIRONO MARU on the Master's Mate Safety Initiative Network?
Not yet. If HIRONO MARU is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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