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.

Towing Vessel

John Jr.

MMSI 367015970 · Call sign WDC3900

Not yet on Master's Mate

Type

Towing Vessel

Flag

USA

Length

14.1 m

Beam

5.5 m

Draft

1.9 m

Call sign

WDC3900

Official No.

524044

AIS reports

John Jr. is an utility vessel flying the American flag, 14.1 metres overall. John Jr. has a beam measuring 5.5 metres and a 1.9-metre draft. Look for MMSI 367015970, call sign WDC3900. Put John Jr. on the free Master's Mate Safety Initiative Network and keep the working fleet looking out for each other.

Free forever · No credit card · for working boats

Built for boats that work — like John Jr..

Engine & systems telemetry, live AIS, weather and distress alerting for the vessels that earn their keep.

Rig her out — free →

Takes 60 seconds · Your data stays yours · Built by cruisers, for cruisers

Wherever John Jr. 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 working boats

The most powerful cruising platform ever built — yours, free.

Joining the Safety Initiative Network doesn't just put John Jr. on the map. It hands you the full bridge:

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.

Weather & Routing

GRIB wind, swell & current on the chart. Plan passages with ETA-calibrated forecasts per leg.

Distress Mesh

Mayday & Pan-Pan that ripple out to nearby cruisers — a watch network that has your back.

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.

Onboard Cameras

Watch your boat from anywhere — live feeds and 24h recording, straight from your gateway.

Hail Any Captain

A verified captains directory + direct hailing. Reach the boat next to you, or across the bay.

Claim John Jr. and switch it all on

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About John Jr.

What kind of vessel is John Jr.?

John Jr. is a Towing Vessel flagged to United States of America.

What is John Jr.'s MMSI?

John Jr.'s MMSI is 367015970. Call sign WDC3900.

How big is John Jr.?

John Jr. is about 14.1 m long, 5.5 m on the beam, drawing 1.9 m.

Is John Jr. on the Master's Mate Safety Initiative Network?

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