Unfortunately, specific information on helicopter ops will be few and far between. The superyachting world, particularly the high end, involves a lot of privicy and confidentiality agreements. A lot of pilots and employees will be afraid to post for fear of losing their job.
In the last few years I've seen almost 10 people involved in this sector fired for postings on face-book.
It's also an area where pilots can be pressured into operating in situations which are unsafe and illegal. 'I wouldn't do that', I hear you cry, well some do and the others go home quickly. Sad but true.
As for hours, some operations have pilots who work ashore and rotate for periods of 4-6 weeks onboard, and are encouraged to fly a few hours a week whilst onboard.