We're talking about singles  

I didn't say anything about OpSpecs, only that things are spelled-out in the Ops Manual, not all of which has to be FAA-approved.  And of course, single-engine night-135 work is not prohibited by the FARs.  However, the Ops Manual will specify when singles can operate.(e.g sunrise to 30 minutes prior to sunset offshore, generally).  Most Gulf of Mexico 135 operators did not allow any offshore night flying in singles when I was there. All the offshore 206/407/350 pilots would've had to be put through an approved night training program and be night current like their EMS counterparts.  PHI was very picky about not wanting/having to do that.  So yeah, there is kind of a difference between 135 and 91 flying. When I was at PHI, "beach+30" applied to all singles no matter what the weather.  If that changed, oh well. Of course, the twins did go offshore at night, even back then. 

The accident we're talking about here was a single. It now looks like it was some sort of pilot-health issue, but we are still interested to know what time this accident occurred, and what WW's single-engine policies are with respect to night flying? If the pilot had the presence of mind to pop the floats and try to land it, did he at least get a radio call off to Ops?