It's bunk.

US law requires manufacturer's and importers of vessels to have light which have been certified to meet USCG requirements.

It says in 33CFR Sub-Part M, paragraph 183.801-8:

§ 183.803 Applicability.
This subpart applies to recreational vessel manufacturers, distributors, and dealers installing such equipment in new recreational vessels constructed after November 1, 2002.

§ 183.803 Definitions.
As used in this subpart: Dealer means any person who is engaged in the sale and distribution of recreational vessels to purchasers who the seller in good faith believes to be purchasing any such recreational vessel for purposes other than resale. Distributor means any person engaged in the sale and distribution of recreational vessels for the purpose of resale. Manufacturer means any person engaged in:
(1) The manufacture, construction, or assembly of recreational vessels, or
(2) The importation of recreational vessels into the United States for subsequent sale.
Navigation lights are those lights prescribed by the Navigation Rules (Commandant Instruction 16672.2 series) to indicate a vessel’s presence, type, operation, and relative heading.

What is interesting to note is that during the hearings and public consultations in 2000 held in regards to creating this piece of regulation, that the goal was specifically not to force all existing lights to be replaced, like the flurry which happened after the US signed and implemented COLREG to the US maritime in the early 80s (some of the lights dating from the 50s and 60s were truely terrible. At the time I had some beautiful bronze ones, but had a range of about 2 feet. I kept the lights on the boats because 'they fit', but also added a tricolour for personal safety).

I have been told (a year ago) that a LEXUS/NEXUS search did not reveal any instance where the certification of lights was a factor in any litigation in the US involving lighting, but rather the required lights were not lit (for whatever reason).

If you operate a vessel in any area governed by COLREG (inland waterways have their own rules), you are required to have lights which comply with COLREG. Failure to do so is illegal (save for military vessels, but, hey, what Marine Patrol guy is going to try to give a ticket to an aircraft carrier? ). COLREG does not have any third party certification requirements.

The guy at Hella is blowing smoke. There is nothing wrong with Hella products, and I'm not running them down, but this guy is full of it.

best,
Michael