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
Back 9 and A Half
MMSI 368398580 · Call sign WDP9357
Not yet on Master's MateFlag
USACall sign
WDP9357
Official No.
1352219
AIS reports
1
Back 9 and A Half flies the American flag — a boat. She's listed under MMSI 368398580, call sign WDP9357. Put Back 9 and A Half on the Master's Mate Safety Initiative Network — free to claim, with a whole fleet watching out for her.
Free forever · No credit card
Is Back 9 and A Half 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 Back 9 and A Half 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 Back 9 and A Half 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 Back 9 and A Half and switch it all on
Free to join · nothing to install to start · cancel anytime
About Back 9 and A Half
What kind of vessel is Back 9 and A Half?
Back 9 and A Half is a vessel flagged to United States of America.
What is Back 9 and A Half's MMSI?
Back 9 and A Half's MMSI is 368398580. Call sign WDP9357.
Is Back 9 and A Half on the Master's Mate Safety Initiative Network?
Not yet. If Back 9 and A Half 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.