Land Immediately.....what is ambiguous about that?
Ditch.....what is the "time" element of that directive? Immediately....delay as needed to organize SAR, divert to nearest assistance (boat, vessel, rig, point of land) or make your call and confirm someone knows your location, intentions, and numbers of persons aboard?
212man raises a good question....it depends upon how you feel about gambling with people's lives! One way you kill some.....the other way you may not kill any....or kill everyone. If you decide using probability....you continue on and roll the dice on an all or nothing wager. If you decide rationally....one could decide to risk as few as possible.
The other question that does not get argued as it should....is when do you stop flying due to the hazards beneath you that make landing out/ditching such a serious gamble? Are we ignoring the patently obivious by putting ourselves in that position? Should we operate in sea states that exceed the certification of the emergency flotation? Should we operate in temperatures (ambient and water) that present a risk of death that exceeds the SAR response time factored for successfully locating and rescuing from an in-water situation?
Get a grip on those questions then talk to me about equipment, training, physical standards, and the rest.
I don't want to hear about "economical issues, we cannot do business if we don't......and that response. Let's put lives first and economics last. Last time I checked we are not fighting a war but rather are in the oil production business. What price/value/worth do we put on human life in this business?