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 H MacMillan Jr
MMSI 366984920 · Call sign WDB9907
Not yet on Master's MateType
Towing Vessel
Flag
USALength
51.7 m
Beam
16.8 m
Draft
3 m
Call sign
WDB9907
Official No.
294692
AIS reports
1
John H MacMillan Jr, a workboat flying the American flag, measures 51.7 metres on deck. She's built with a 16.8-metre beam and a 3 m draft. On AIS she appears as MMSI 366984920, call sign WDB9907. Join John H MacMillan Jr to the Master's Mate Safety Initiative Network — free, and built by cruisers for cruisers.
Free forever · No credit card · for working boats
Built for boats that work — like John H MacMillan 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 H MacMillan 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 H MacMillan 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 H MacMillan Jr and switch it all on
Free to join · nothing to install to start · cancel anytime
About John H MacMillan Jr
What kind of vessel is John H MacMillan Jr?
John H MacMillan Jr is a Towing Vessel flagged to United States of America.
What is John H MacMillan Jr's MMSI?
John H MacMillan Jr's MMSI is 366984920. Call sign WDB9907.
How big is John H MacMillan Jr?
John H MacMillan Jr is about 51.7 m long, 16.8 m on the beam, drawing 3 m.
Is John H MacMillan Jr on the Master's Mate Safety Initiative Network?
Not yet. If John H MacMillan Jr 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.