What was in force there, then?
A position, a moment in UTC and a radius. The answer is what this archive holds for that moment, with when each message was collected, and a statement of what was being collected at all.
What you get
| in force | every warning we hold that was issued before and cancelled after the moment, whose area or position lies within the radius |
| collected | when this archive first and last saw the message, and how its cancellation is known (explicit, self-cancel, dropped from the in-force list, archive) |
| coverage | for the series that report this sea: archive, Wayback capture, live collection or nothing at that moment — so an empty answer is never mistaken for a quiet sea |
Not for navigation, and not a legal record: a statement about what this archive holds. Official broadcasts are authoritative.