I'm still on a learning curve when it comes to the Silver Surfer, so need some clarification please! The Fantastic Four movie seems to suggest that if he is separated from his board, he loses his powers. In the Planet Hulk story, the Surfer had the board strapped to him and didn't have the power cosmic, however I think this was due to the disc that was on him. So how weak is the Surfer when separated from his board and does he have to actually be standing on it to get full power? The FF movie made him appear really weak without a board, whereas in the Planet Hulk book, he wasn't scratched by anything even when not stood on his board and denied the power cosmic. By comparison, the Hulk was bleeding after the Surfer head butted him!
I'm assuming the FF movie just downgraded the Surfer's abilities, because my research indicates he is still a tough dude without that board.