In 2016 Shark seats were tested at a UK MOD facility (RAFCAM) for shock mitigation performance. This testing includes very severe drop tests such as a 2 metre drop into a sandbox as shown in this video. This drop represents a 10G impact from a RHIB flying over a 2 metre wave at high speed with a 100kg passenger.
To make this test even harsher, the dummy passengers legs dangle so that all 100kgs of weight bears on the seat during impact. In testing standards it is normal to rate this as equivalent to the impact from a human being 30% heavier (or 130kg). This is the basis upon which shark rates its suspension for passengers up to 120kg with impacts up to 10G.
As far as we are aware, shark is the only shock mitigating boat seat manufacturer to publish such a rating for its suspensions and the only manufacturer to publish video evidence.