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.
Recreational
J SEA IV
MMSI 367751990 · Call sign WDI9770
Not yet on Master's MateType
Recreational
Flag
USALength
21.7 m
Beam
5.9 m
Draft
3 m
Call sign
WDI9770
Official No.
1272522
AIS reports
1
Out of the United States, J SEA IV is a 21.7-metre private vessel. Her hull carries a 5.9 m beam and a draft of 3 m. Her papers read MMSI 367751990, call sign WDI9770. J SEA IV belongs on the Master's Mate Safety Initiative Network, a free safety net shared by boats the world over.
Free forever · No credit card · for recreational captains
Keep J SEA IV looked after — even when you’re not aboard.
Anchor alarms that wake you, a live camera at the dock, and weather you can trust before every run.
Look after her — claim free →Takes 60 seconds · Your data stays yours · Built by cruisers, for cruisers
Wherever J SEA IV 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 · for recreational captains
The most powerful cruising platform ever built — yours, free.
Joining the Safety Initiative Network doesn't just put J SEA IV 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.
Onboard Cameras
Watch your boat from anywhere — live feeds and 24h recording, straight from your gateway.
Weather & Routing
GRIB wind, swell & current on the chart. Plan passages with ETA-calibrated forecasts per leg.
Worldwide Charts
Navionics-grade vector charts, satellite & raster overlays, online or off. Your whole cruising ground.
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.
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 J SEA IV and switch it all on
Free to join · nothing to install to start · cancel anytime
About J SEA IV
What kind of vessel is J SEA IV?
J SEA IV is a Recreational flagged to United States of America.
What is J SEA IV's MMSI?
J SEA IV's MMSI is 367751990. Call sign WDI9770.
How big is J SEA IV?
J SEA IV is about 21.7 m long, 5.9 m on the beam, drawing 3 m.
Is J SEA IV on the Master's Mate Safety Initiative Network?
Not yet. If J SEA IV 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.