JP raised a question about how COLREGS can apply to a seaplane when it is not physically on the surface of the water. There are already lots of regulations for aircraft; does a seaplane have to follow the COLREGS even when flying safely along and complying with aviation regulations?
This was triggered by a question in one of the quizzes.
The enabling legislation in Canada includes the following text in the section on Application:
"3 (1) Subject to subsection (2), these Regulations [COLREGS] apply in respect of
...
(c) every seaplane on or over Canadian waters." [Emphasis added.]
See: https://laws-lois.justice.gc.ca/eng/regulations/c.r.c.,_c._1416/page-1.html#h-512767
When the seaplane is on the surface, there is really little ambiguity (treat it like a boat). But what if it is over water? It would appear that it could be subject to COLREGS even if it is at 10 000 ft and cannot even see any boat traffic way below.
I believe that "or over" is included is to ensure that a seaplane will keep clear of other boating traffic even if has not quite touched down. Or to find a pilot is liable if the pilot is taking off and has just become airborne, but makes contact with a boat (that the seaplane should have avoided... by following COLREGS).
Note that most of the manoeuvring rules (R11 to R19) include a phrase like the rule applies when conditions exist "so as to involve risk of collision". Clearly a seaplane at 10 000 ft has no risk of collision with a boat on the surface of the water. So a rule like that would not apply. Now if it is about to land (say at 50 ft and descending), the seaplane should be required to follow the rules even before touchdown.
So, there is some ambiguity about it. And assessing a risk of collision, except in very clear situations, often raises some debate for hypothetical situations. For real situations, in the past, one way to determine if there was risk is whether a collision occurred. If YES, then a risk existed before the event.
Discussion? Questions? .... Are there other areas of ambiguity you have found in the COLREGS?