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
KAI-OH MARU
MMSI 431013119 · Call sign JD4503
Not yet on Master's MateType
Cargo
Flag
JPNLength
191 m
Beam
27 m
Draft
6.3 m
Call sign
JD4503
IMO
9846172
First reported
Jun 2026
Last reported
Jun 2026
AIS reports
18
KAI-OH MARU is a Japanese 191-metre general cargo ship. She has a 27-metre beam and a draft measuring 6.3 metres. Find her under MMSI 431013119, call sign JD4503, IMO 9846172. KAI-OH MARU is welcome on the Master's Mate Safety Initiative Network — a free, community-run watch where boats look out for one another.
Free forever · No credit card · for commercial operators
Eyes on KAI-OH 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
35.9097° N, 140.9420° 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 KAI-OH 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 KAI-OH MARU and switch it all on
Free to join · nothing to install to start · cancel anytime
About KAI-OH MARU
What kind of vessel is KAI-OH MARU?
KAI-OH MARU is a Cargo flagged to Japan.
Where was KAI-OH MARU last seen?
KAI-OH MARU was last reported in the Sea of Japan in Jun 2026 on public AIS.
What is KAI-OH MARU's MMSI?
KAI-OH MARU's MMSI is 431013119. Call sign JD4503. IMO 9846172.
How big is KAI-OH MARU?
KAI-OH MARU is about 191 m long, 27 m on the beam, drawing 6.3 m.
Is KAI-OH MARU on the Master's Mate Safety Initiative Network?
Not yet. If KAI-OH MARU 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.