I called the Boating Safety Officer at the District 13 Headquarters here in Seattle yesterday. He told me that oil lamps do not currently meet the requirments as none that he knows of are stamped "USCG Approved". I asked him what you do for a boat with no electrical system, and he said "Install USCG Approved electric lights when you add an electrical system." Oil lamps are acceptable as a backup to electric lights as well. When asked about fire hazard around refineries, he said that as far as he knows, it's not an issue.
Toward that end, it seems to me that if Den Haan wanted to go through the process of getting their lamps certified, they should be legal. It also seems to me that if one could demonstrate that they meet the requirements (visible at two miles I believe), then they would be acceptable.
When I asked him about the electric nav lights that I currently have that ARE NOT stamped, approved lights, he said they would be acceptable until such time as I needed to replace them.
The lights I currently have are small, teardrop shaped, cast bronze with a one inch high lens, mounted on the cabin side, less than a foot above the deck. It seems to me that a four inch lens and an oil lamp and proper reflector, mounted on a dorade box on the coachroof is going to be much more visible than what I currently have.
So, I am going to keep my (IMHO) inadequate electric lights that ARE NOT stamped as approved, and add the oil lamps in the dorades. At the very least I can claim an electrical failure on my nav light circuit, and (hopefully) be commended for having backups. In the meantime, I intend to work with the CG Officers and see if there is some way a case-by-case approval can be worked out. Afterall, unstamped oil lamps that can be seen at two miles are better than unstamped electric lights that cannot be seen at two miles.