How do you get to the sea craven?

No one has yet been able to get back to the sea cavern once you pass it in the game. I even started the game over and it will not let you linger there to get extra fossils. It lets you pick up two or three on the way over to,the pillar, then you inject the calcium into the pillar and you're gone back to Joe's office. The fossils listed as coming from sea cavern in the fossilary get scattered over the rest of the sites. Then they become one of those very rare fossils that you have to visit the same site multiple times before you can find them. If you have access to a second DS and the original game, you can get fossil rocks from the original fossil fighter's game and send them to the new game via the fossil cannon, but this only goes one way-you can't send fossils from the new game back to the old one. In fact, I think only the heads are available from the sea cavern fossils, so if you want the rest of the body parts, you kind of have to use the old game to get them. Read over some of the other questions for info on where you can find sea cavern fossils post game. Hope this helped.