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

Sparrow

MMSI 366904580 · Call sign WDB4991

Not yet on Master's Mate

Flag

USA

Call sign

WDB4991

Official No.

572921

AIS reports

On the American registry, Sparrow is a craft. She's on record as MMSI 366904580, call sign WDB4991. Claim Sparrow free on the Master's Mate Safety Initiative Network and let nearby cruisers have her back.

Free forever · No credit card

Is Sparrow 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 Sparrow 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 Sparrow 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 Sparrow and switch it all on

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

Claim free → unlock everything

About Sparrow

What kind of vessel is Sparrow?

Sparrow is a vessel flagged to United States of America.

What is Sparrow's MMSI?

Sparrow's MMSI is 366904580. Call sign WDB4991.

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

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