Summary
MotionInfo's StationKeeper shore aids-to-navigation transmit AIS safety-related text messages to vessels underway. This report presents two independent bodies of evidence: (1) live delivery-receipt range results from July 2026 trials aboard research vessels and the NOAA Ship Nancy Foster, and (2) an audit of real, unsolicited Message 12 replies that commercial and pilot-guided vessels sent back to StationKeeper stations acknowledging the NOAA right-whale 10-knot speed rule.
The two-way exchange with the Maine Maritime Academy training ship TS State of Maine is documented separately — see the TS State of Maine two-way report.
Delivery-Receipt / Acknowledgement Range
Each row records a confirmed receipt: a vessel received a shore AtoN broadcast and its acknowledgement / AIS position was received back at a StationKeeper station. Range is the vessel-to-station distance at the moment of receipt.
| Vessel | MMSI | Receiving station | Receipt (UTC) | Pos gap | Range (nm) | Range (km) | SOG (kn) |
|---|---|---|---|---|---|---|---|
| R/V Sharp | 367063060 | 4015 — MERR Institute, Lewes DE | 07-01 19:59:27 | 30 s (A) | 0.13 | 0.25 | 0.1 |
| R/V Palmetto | 338004751 | 4159 — Sullivan's Island SC | 07-01 19:42:47–19:43:00 (×3) | 49–61 s (B) | 2.28 | 4.21 | 0.1 |
| R/V Joanne Daiber | 338169577 | — | — | 0 s (A) | 3.63 | 6.73 | 0.6 |
| NOAA Ship Nancy Foster | 369912000 | — | — | 2 s (A) | 5.59 | 10.35 | 7.7 |
| R/V Savannah | 303117000 | 4236 — Wassaw NWR GA | 07-01 16:06:23 | 1 s (A) | 14.62 | 27.07 | 9.0 |
| R/V Savannah | 303117000 | 4144 — Tybee Island GA | 07-01 16:06:28 / 16:20:53 / 16:20:59 | 0–2 s (A) | 14.26→15.85 | 26.4–29.4 | ~9 |
Pos gap — interval between the vessel's transmitted AIS position and the receipt (position freshness; smaller is tighter). Annotations (A)/(B), (×3) and the arrow (→) / hyphen ranges are reproduced verbatim from the corrected range-test log; the arrow and hyphen ranges denote values across multiple receipts. Receipt times are UTC.
Real Ship-to-Shore Replies — Vessels Acknowledging the Speed Rule
Beyond the planned trials, MotionInfo audited every AIS Message 12 (addressed safety-related text) in its archive — 834,514 rows spanning 2024-07-09 through 2026-09-04 — and isolated messages that vessels sent to a StationKeeper station and that were not part of any test. The result is a record of real, unsolicited ship-to-shore acknowledgements of StationKeeper right-whale speed advisories.
18 distinct non-test replies from 17 vessels, addressed to 8 different StationKeeper stations. Nearly all respond to the NOAA North Atlantic right whale 10-knot rule (50 CFR 224.105): acknowledgements, confirmations of slowing, pilot-exemption notices and speed-deviation declarations. Every reply was captured on the independent receive site 50010, and in most cases also on the nearby StationKeeper's own feed — genuine over-the-air receipts, not loopback.
A representative selection:
| Date (UTC) | From (vessel MMSI) | To (station MMSI) | Message text (as received) | Received on site(s) |
|---|---|---|---|---|
| 2025-03-31 | 636093244 | 993667008 | WELL RCVD, WE SLOW TO 10KN | 50010 |
| 2025-11-02 | 636016415 | 993667006 | FOLLOWING PILOT ADVICE | 50010, 54031 |
| 2025-11-26 | 636020837 | 993667073 | FROM 30 APRIL TO NOVEMBER 01 / MAX SPEED 10KTS PER US LAW 50CFR224.105 | 50010, 54154 |
| 2026-01-06 | 255805563 | 993667006 | WE HAVE PILOT EXEMPTION. THNK YOU. | 50010, 54031, 54173 |
| 2026-02-25 | 636023553 | 993667006 | WELL NOTED, WE ARE REDUCING SPEED. THANKS. | 50010, 54031 |
| 2026-07-03 to 07-06 | 338924010 TS STATE OF MAINE | 993660511 shared real AtoN | STATE OF MAINE ACKNOWLEDGES / STATE OF MAINE ACK / ACK (~28 rows) | 50010, 54154, 54155, 54197, 54201, 54223, 54226, 54142 |
Selected from the full audit of 18 non-test replies. Trailing fill characters from AIS 6-bit encoding have been trimmed; sender typos are kept as received. Repeated text reflects a vessel's Class A retransmitting until acknowledged, or reception on multiple sites.
TS State of Maine — sent from Navesink (Twin Lights) Lighthouse
The July 2026 acknowledgements from the Maine Maritime Academy training ship TS State of Maine (MMSI 338924010) were replies to messages transmitted from MotionInfo's Navesink (Twin Lights) Lighthouse station in Highlands, NJ. The ship returned its acknowledgement to the network:
"STATE OF MAINE ACKNOWLEDGES" / "STATE OF MAINE ACK" / "ACK"
Why This Matters
- Delivery is confirmed, not assumed. Receipts came back over the vessels' real operating ranges — out to ~15–16 nm — on research vessels and a NOAA ship.
- Real mariners are already responding. Commercial cargo, tanker and pilot-guided vessels sent unsolicited replies acknowledging the 10-knot rule — evidence the messaging reaches and is acted on by the operational fleet, not just test platforms.
- Independent capture. Every reply was received on an independent site (50010) plus, usually, the local StationKeeper feed — confirming genuine over-the-air reception.
References
Companion report — TS State of Maine two-way AIS exchange →
Companion report — UNH research vessel AIS message testing →
StationKeeper AIS Messaging Tests — Delivery-Receipt Range Results (PDF) →
NOAA Fisheries — Messaging Mariners in Real Time to Reduce Right Whale Vessel Strikes →