Not that it is the same as Offshore racing, but he has experience racing Motocross. I have some friends that went riding with him on a track here in So. Cal. last year and they said he is fast, Probably has enough skill to race at the local Pro level.
With this type of racing experience I think he would be a little more skilled than somebody with none. More than a few ex-pro motocross riders have transitioned into other motorsports. Look at jeff ward, who was a factory rider for Kawasaki for years, he nearly won the Indy 500 a few years back.