Since no one has leapt to answer your question you are, no doubt, beginning to suspect that this might be a rather tricky situation. Steve and I have for years tried to help mountain guides with their training. Like you, they have physically demanding jobs and unusual working schedules that makes adhering to the “Three Cardinal Principles” that separate Training form Exercise. Those principles are:
Continuity: Regular with no breaks
Gradualness:Gentle progression in overload
Modulation: Variations in load
Without these 3 things it is almost impossible to construct a viable training plan. All is not lost though. Exercise and well crafted exercise can still get you a long way. In your case you need to make the most of the time off the boat to train specific climbing skills/fitness that you need for whatever your goals are. Hopefully your hard work on the boot will serve to maintain some of that fitness.
There is just no magic.