First you must go to the beach and defeat everyone. That includes the people in the beach house. Then you head to the ship building and talk to the man in there. They should then be gone. If not, are you not talking about Pokemon? :/
get natinol dex!
Get the natinal dex
get the HM Defog
beat the freakin elite 4 get the nat dex
Complete the pokedex.
I just used a cheat to walk anywhere but I think you have to do something in the areas next to it like the Battle Frontier and the resort area.
if you mean in Pokemon diamond/pearl/platinum you need to get the national dex!
You have to beat fantina the 3 gymleader then they move.
There is, in fact, no route past route 24
you need to fight them to get past
No you cant
Fill your sinnoh pokedex. I'm still working on that...