Well, it seems as if there may be about four of us who are interested in helicopters and yachts - I supposed its enough to continue with. Just one other person would have been fine with me, lol!
Firstly on the matter of boredom. Yes, if you are recruited full time to fly two weeks in summer and another two in the winter then you're going to get fed up pretty quickly but, the number of scenarios where this is the case are few and far between to the best of my knowledge.
What usually happens is one of the following:
Many yacht owners simply charter helicopters from the locations they cruise and, given that the routine for the vast majority of large yacht owners is the Med in summer and the Caribbean in winter, there are no shortage of operators on hand to provide this service. St.Tropez, Nice and Monaco all serve this market along the magical Côte d'Azur.
Where the owner feels that he needs his own flying tender, the two most common solutions are that the rotorcraft is either placed with an operator near the yacht's normal home port when not engaged in yacht operations or, that the rotorcraft is utilised by the owner for onshore operations in between yachting assignments.
In the case of Allen and Ambramovich; Allen's helicopters tend to stay fairly close to his yachts whereas Abramovich's aircraft are deployed all over Europe on an almost endless routine supporting not only the 'Abramovich Navy' but also the European interests of Abramovich's business empire.
With regard to yacht helicopter operations specifically it would be wonderful if an experienced yacht-helicopter pilot could enlighten us with first hand information of some of the details involved.
On the matter of colour coding between yachts and their helicopters - yes, this is crucial! Many 'Yopters' also wear the vessel's name in much the same way as water borne tenders.
The MY Princess Mariana owned by Mexican telecoms mogul Carlos Peralta. Just above the waterline you will observe a discreet double stripe in pale turquoise. The same double stripe is repeated in scale on the on-board EC130. As stated before, this colour coordinating is most important in yacht-helicopter operations. 
Still lots more information, photos and videos to come and which I shall drip feed into the thread along the way!
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