Concur with zalt. It's not only the "safe water landings" that get hidden. Aircraft running into each other and obstacles on GoM platforms with never a mention in the NTSB/FAA records are also not counted, as long as it is only main or tail rotor damage.
I was working on getting money to upgrade our helidecks, and had a senior HSE manager tell me that the GoM had no recent history of helideck design related incidents. It's maddening.