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
Sonder
MMSI 368064920 · Call sign WDK5452
Not yet on Master's MateType
Recreational
Flag
USALength
12.3 m
Beam
4.1 m
Draft
3.3 m
Call sign
WDK5452
Official No.
1076270
AIS reports
1
Registered in the United States, Sonder is a 12.3-metre family boat. Sonder has a beam measuring 4.1 metres and a 3.3-metre draft. On AIS she shows as MMSI 368064920, call sign WDK5452. Claim Sonder free on the Master's Mate Safety Initiative Network and let nearby cruisers have her back.
Free forever · No credit card · for recreational captains
Keep Sonder 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 Sonder 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 Sonder 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 Sonder and switch it all on
Free to join · nothing to install to start · cancel anytime
About Sonder
What kind of vessel is Sonder?
Sonder is a Recreational flagged to United States of America.
What is Sonder's MMSI?
Sonder's MMSI is 368064920. Call sign WDK5452.
How big is Sonder?
Sonder is about 12.3 m long, 4.1 m on the beam, drawing 3.3 m.
Is Sonder on the Master's Mate Safety Initiative Network?
Not yet. If Sonder is your boat, you can claim it free and join the Master's Mate Safety Initiative Network (MMSIn).
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