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
HARBORMASTER BOAT 4
MMSI 366877070 · Call sign WXZ5431
Not yet on Master's MateFlag
USACall sign
WXZ5431
Official No.
MC1336PB
AIS reports
1
On the American registry, HARBORMASTER BOAT 4 is a craft. On AIS she appears as MMSI 366877070, call sign WXZ5431. Give HARBORMASTER BOAT 4 the backing of the Master's Mate Safety Initiative Network — free, and a fleet that has her back.
Free forever · No credit card
Is HARBORMASTER BOAT 4 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 HARBORMASTER BOAT 4 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 HARBORMASTER BOAT 4 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 HARBORMASTER BOAT 4 and switch it all on
Free to join · nothing to install to start · cancel anytime
About HARBORMASTER BOAT 4
What kind of vessel is HARBORMASTER BOAT 4?
HARBORMASTER BOAT 4 is a vessel flagged to United States of America.
What is HARBORMASTER BOAT 4's MMSI?
HARBORMASTER BOAT 4's MMSI is 366877070. Call sign WXZ5431.
Is HARBORMASTER BOAT 4 on the Master's Mate Safety Initiative Network?
Not yet. If HARBORMASTER BOAT 4 is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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