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
Koyo Maru No. 15
MMSI 431817000
Not yet on Master's MateFlag
JPNLength
63 m
IMO
9020807
AIS reports
2
Koyo Maru No. 15, a Japanese craft, measures 63 metres on deck. Officially she's MMSI 431817000, IMO 9020807. Claim Koyo Maru No. 15 free on the Master's Mate Safety Initiative Network and let nearby cruisers have her back.
Free forever · No credit card
Is Koyo Maru No. 15 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
Wherever Koyo Maru No. 15 roams, 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 Koyo Maru No. 15 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 Koyo Maru No. 15 and switch it all on
Free to join · nothing to install to start · cancel anytime
About Koyo Maru No. 15
What kind of vessel is Koyo Maru No. 15?
Koyo Maru No. 15 is a vessel flagged to Japan.
What is Koyo Maru No. 15's MMSI?
Koyo Maru No. 15's MMSI is 431817000. IMO 9020807.
How big is Koyo Maru No. 15?
Koyo Maru No. 15 is about 63 m long.
Is Koyo Maru No. 15 on the Master's Mate Safety Initiative Network?
Not yet. If Koyo Maru No. 15 is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
© 2026 Master’s Mate. All rights reserved.