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
Upper Left
MMSI 368276220 · Call sign WDN3913
Not yet on Master's MateType
Recreational
Flag
USALength
12.3 m
Beam
4 m
Draft
1.8 m
Call sign
WDN3913
Official No.
1253363
Hull ID
IRISG027H314
AIS reports
1
Upper Left flies the American flag — a 12.3-metre pleasure craft. Upper Left has 4 metres in the beam and a 1.8 m draft. On AIS she shows as MMSI 368276220, call sign WDN3913. Upper Left is welcome on the Master's Mate Safety Initiative Network — a free, community-run watch where boats look out for one another.
Free forever · No credit card · for recreational captains
Keep Upper Left 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 Upper Left 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 Upper Left 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 Upper Left and switch it all on
Free to join · nothing to install to start · cancel anytime
About Upper Left
What kind of vessel is Upper Left?
Upper Left is a Recreational flagged to United States of America.
What is Upper Left's MMSI?
Upper Left's MMSI is 368276220. Call sign WDN3913.
How big is Upper Left?
Upper Left is about 12.3 m long, 4 m on the beam, drawing 1.8 m.
Is Upper Left on the Master's Mate Safety Initiative Network?
Not yet. If Upper Left 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.