For those that are interested in how the intent of the law is meant to be used I give you the following
Frequently asked Questions it is a 298 page (takes a while to download) document and describes the FAA Flight Standards Service policy as it relates to a regulation.
On page 65/66 I found the following senario and it very closely covers our offshore, no visible horizon and how it relates to regulations.
QUESTION: The question came up about logging “actual” instrument time when over the desert at night with no visual references. When you are flying with sole reference to instruments, is that actual time? If not, is it “simulated” instrument time? Our take on the question is actual instrument time can only be logged when the aircraft is in IMC. The weather determines actual instrument time, not flying by sole reference to instruments. That settles the actual instrument question, but what about “simulated” instrument time? Our feeling is it can be logged as “simulated instrument time.” It would be the same as having a hood on while flying by sole reference to instruments. What about the requirement for a safety pilot under these conditions? Our answer is "no" because the pilot is still able to "see and avoid" conflicting traffic.
ANSWER: Ref. §61.51(g); The only definition in the rules is the definition on “instrument flight time” and that is addressed in §61.51(g) and is defined as: (g) Logging instrument flight time.
(1) A person may log instrument time only for that flight time when the person operates the aircraft solely by reference to instruments under actual or simulated instrument flight conditions. However, I understand your question to be that you’re asking for a definition of “actual instrument time” as opposed to “simulated instrument time.” I believe you’re interchanging the terms “actual instrument time” where the rules only state “actual instrument conditions.” And you state “simulated instrument time” but the rules only state“simulated instrument conditions.” So there is no official FAA definition on “actual instrument time” or “simulated instrument time” in the FARs, FAA Orders, advisory circulars, FAA bulletins, etc. And the reason why the FAA has never officially defined “actual instrument time” or “simulated instrument time” is because in all of the aeronautical experience requirements for pilot certificate and/or ratings in Part 61, the rule does not differentiate between “actual instrument time” as opposed to “simulated instrument time.” In fact, in Part 61 it only refers to the aeronautical experience for instrument time to be “. . . instrument flight time, in actual or simulated instrument
conditions . . .” So it is irrelevant whether the instrument flight time is logged as “actual instrument time” or “simulated instrument time.” Part 61 only refers to “actual instrument conditions” or “simulated instrument conditions.” I agree with your statement that just because a person is flying “. . . by sole reference to instruments . . .” has nothing to do with whether the flight can be logged as “actual instrument time” or “simulated instrument time.” Only the weather conditions establish whether the flight is in “actual instrument conditions.” And that is dependent on the weather conditions where the aircraft is physically located and the pilot makes that determination as to whether the flight is in “actual instrument conditions” or he is performing instrument flight under “simulated instrument conditions.”
But for a “quick and easy” answer to your question, it was always my understanding if I were flying in weather conditions that were less than the VFR weather minimums defined in §91.155 and I was flying “solely by reference to instruments” then that was the determining factor for being able log instrument flight under “actual instrument conditions.” Otherwise, if I were flying solely by reference to instruments in VMC conditions then I would log it as instrument flight in “simulated instrument conditions.” In your example, the flight is clear of clouds and in good visibility conditions at night over the desert with an overcast above and no visible horizon. But other examples could include flight between sloping cloud layers or flight between layers of clouds at night. These could equally meet the requirement for operations that can only be accomplished solely by reference to instruments. But, the lack of sufficient visual reference to maintain aircraft control without using instruments does not eliminate the possibility of collision hazard with other aircraft or terrain. So, now to answer your other question “What about the requirement for a safety pilot under these conditions? Your question is answered by §91.109(b)(1) and it states: “(b) No person may operate a civil aircraft in simulated instrument flight unless— (1) The other control seat is occupied by a safety pilot who possesses at least a private pilot certificate with category and class ratings appropriate to the aircraft being flown.” Normally, in order to log instrument flight time under “simulated instrument conditions,” the pilot needs to be utilizing a view limiting device. But, the only place in the rules requiring a view limiting device will be found under §61.45(d)(2) as part of the equipment for a practical test. Otherwise, no where else in the rules, orders, bulletins, or advisory circulars does it specifically state that pilots need to be utilizing a view limiting device. But, except for meteorological conditions as in our examples above, how else, could a pilot comply with §61.51(g) for logging instrument flight time [i.e., “. . . when the person operates the aircraft solely by reference to instruments . . .”] unless the pilot was utilizing a view limiting device when logging instrument flight time in simulated instrument conditions?