From the Canadian side, very close to the numbers crab mentioned. For the last helicopter purchase, minimum performance was a 200nm radius with 30min on scene. Actual capability exceeds that, especially on the Atlantic where off shore platforms can be used to refuel.
Any boat that is rocking and has antennas/masts/outriggers reaching up high forces your hoist height to be high. We used to go lower for better references, but that was in a SAS only aircraft with no autopilot functions. With higher order FCS and good crew communication, good references are less of a consideration, but still desirable.