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

A4Sea

MMSI 367467780 · Call sign WDF5842

Not yet on Master's Mate

Flag

USA

Call sign

WDF5842

Official No.

1214675

AIS reports

A4Sea is a boat flagged in the United States. On AIS she shows as MMSI 367467780, call sign WDF5842. Join A4Sea to the Master's Mate Safety Initiative Network — free, and built by cruisers for cruisers.

Free forever · No credit card

Is A4Sea 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 A4Sea 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 A4Sea 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 A4Sea and switch it all on

Free to join · nothing to install to start · cancel anytime

Claim free → unlock everything

About A4Sea

What kind of vessel is A4Sea?

A4Sea is a vessel flagged to United States of America.

What is A4Sea's MMSI?

A4Sea's MMSI is 367467780. Call sign WDF5842.

Is A4Sea on the Master's Mate Safety Initiative Network?

Not yet. If A4Sea is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).