Definitely think its an aircraft warning light, this is a snippet from some FAA requirements
Any temporary or permanent structure, including all
appurtenances, that exceeds an overall height of 200
feet (61m) above ground level (AGL) or exceeds any
obstruction standard contained in 14 CFR part 77,
should normally be marked and/or lighted. However,
an FAA aeronautical study may reveal that the
absence of marking and/or
lighting will not impair
aviation
safety. Conversely, the object may present
such an extraordinary hazard potential that higher
standards may be recommended for increased
conspicuity to ensure
safety to air
navigation.
Normally outside
commercial lighting is not
considered sufficient reason to omit recommended
marking and/or lighting. Recommendations on
marking and/or lighting structures can vary
depending on terrain features,
weather patterns,
geographic location, and in the case of
wind turbines,
number of structures and overall layout of design.
The FAA may also recommend marking and/or
lighting a structure that does not exceed 200 (61m)
feet AGL or 14 CFR part 77 standards because of its
particular location
When you think about it, superyachts and helicopters go together nowadays.
Personally, I think its all about shouting out "hey, look, mines bigger than yours"
Oh, and white over red, that's the lights for a pilot vessel, not a vessel under pilotage.
Red over white, frying tonight
White over red, pilot ahead