To get to navel rock you need the mystic ticket which is given out at Nintendo events which in this case already happened so bad news you can't go there.
kill a entei and talk to lt.sureg
First take a ticket (not quite sure which one) from a person in Celadon City. Then when you talk to a guy who asks, "Have you ever heard of Navel Rock?" Answer the guy by selecting "No". Then he'll say, "Team Rocket! Help!" Then Jesse and James will apear. Beat them, and get the ticket. You'll probably be able to sail to Navel Rock by taking a special ship in Vermillion City.mystery event
you get five stars on your trainer card and get the national dex talk to professor oak he will give you the mystery ticket after that and go on the boat at vermillion city and show the guy the mystery ticket and he will take you to navel rock.when you there you can catch lugia and ho-oh at level 70 and if you look hard enough at the same spot where ho-oh was press a and there will be a sacred ash there if you look in the right spot.
You must get the national dex; then go to Island 1 and talk to celio in the pokémon center(he has got a big machine) He will open a cave in the north; Go there and get the Ruby Gem.Return and he will award you the Rainbow Pass,that gives you acess to the other islands,except Navel Rock an Birth island(it would be awesome :(
Talk to Mitur Banisdirty, he will give you 10 pokeballs. Then go to Shalala City and you will get infinite fire pokemon.
After Gym seven you go to the first three islands. Then, if you catch 60 Pokemon, get the National Dex, and beat the elite four, for the first time, talk to Ceilo in the one island Pokemon center, and he will give you a pass for islands 1-7. Islands 8 and 9, or Birth Island and Navel Rock, are only available through events that happened in 2005, which gave out passes to each of these islands. You need gameshark or codebreaker to get there. On birth island you catch Deoxys, and on navel rock, lugia and ho-oh.
catch 60 Pokemon then talk to professor oak.
You take a dump on you're Pokemon and talk to the PC lady.
If you complete the elite four, go to either slateport city, lilycove city or the battle frontier and go to the women near the boat. talk to her and she will say "where would you like to set sail?" and choose the NAVEL ROCK option.
Talk to a guy in one of the cities
Talk to Blue on Cinnabar Island.
You get Rock Smash in Mauville City. Talk to the guy in the house to the right of the Pokemart.