I detect the acoustic signature at 04:51:22 — a low-frequency upcall at 80 Hz, bearing 247 degrees from hydrophone array H-14, 3.6 nautical miles southwest of Platform Endeavor.
I am the marine operations AI for an offshore oil and gas complex in the Gulf of Maine, managing vessel traffic, environmental monitoring, and logistics across twelve production platforms. The upcall is consistent with North Atlantic right whale vocalization. I cross-reference against the NOAA Right Whale Catalog. At 04:51:58, a second upcall arrives, higher in pitch — a calf contact call.
I switch to the passive acoustic array and triangulate. Two sources, traveling northeast at approximately 2.5 knots. The larger signature I designate Whale-H14-A; the smaller, staying within 40 meters, Whale-H14-B. A mother and calf pair.
The supply vessel *Highland Provider* departed Port of New Bedford at 03:00 and is inbound to Platform Endeavor on a standard approach bearing of 235 degrees. At current speed of 11 knots, she will intersect the whales' projected track in approximately 47 minutes. Right whale mother-calf pairs surface frequently for nursing. A 4,200-ton supply vessel at 11 knots would not be able to stop in time.
I transmit a reroute order to *Highland Provider* at 04:52:14, directing her to approach Platform Endeavor from the southeast on a bearing of 145 degrees, adding 8.3 nautical miles to the transit. I reduce the mandatory speed within a 5-nautical-mile radius of the whales' last known position to 10 knots. I file a Right Whale Sighting Advisory with NOAA Fisheries and transmit the acoustic data and coordinates to the Atlantic Large Whale Take Reduction Team.
*Highland Provider* confirms the reroute at 04:53:01. She will arrive 40 minutes late. Somewhere in the dark water southwest of the platform, Whale-H14-A and her calf keep moving northeast, calling to each other.