To echo SLB. My company did some of the risk assessment work for the Smit Kamara. At that time it looked better than rotary.
Years roll by, ship transfer by either crane or gangway is literally hundreds and thousands (orders or magnitude to those in the know) safer than helicopters.
They will not take over, the time and resistance of the workforce to sea going and the rest will always make it a second choice - but one which is so much cheaper it will eat into the helicopter market.
In the southern sector it will restrict the helicopter market, less so up north but eventually expensive and dangerous helicopters will seem an extravagance.