I just came back from the RV "Polarstern" last week. We where operating between S 35° and S 53° in the Atlantic Ocean (not the calmest area ;-))
Our cruise was from Punta Arenas (Chile) to Capetown (SA) and took about 9 weeks (no land in sight for 8,5 weeks)
There are two BO105 CBS 5 stationed on the vessel. We did a lot of flying for earth magnetic measurements with a sensor about 100' below the helicopter.
Take-offs and landings are performed up to about 30 kts relative wind. Without sling load we do it up to 40 kts. I didn'd really look what the bank of the ship was but I think something around 10° to 15° either side is ok for a 105. We have a rope net on the helideck and tie it down all the time when on the ground. I personally love flying from the ship.