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

Sheffield

MMSI 636017691

Not yet on Master's Mate

Flag

LBR

Length

187.8 m

IMO

9483205

AIS reports

Sheffield, a Liberian vessel, measures 187.8 metres on deck. Find her under MMSI 636017691, IMO 9483205. Sign Sheffield up free to the Master's Mate Safety Initiative Network and join a fleet that looks after its own.

Free forever · No credit card

Is Sheffield 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 Sheffield 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 Sheffield 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 Sheffield and switch it all on

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

Claim free → unlock everything

About Sheffield

What kind of vessel is Sheffield?

Sheffield is a vessel flagged to Liberia.

What is Sheffield's MMSI?

Sheffield's MMSI is 636017691. IMO 9483205.

How big is Sheffield?

Sheffield is about 187.8 m long.

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

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