you have to beat the elite four first then the guy will let you on.
beat the elite four
beat the elite 4 then go back to the boat
You need to complete the Pokemon league
Go to Snowpoint City and take the boat there to the Battle Zone.
you have to beat the elite four and go to the sailor with the boat in snowpoint city.
If you don't have the National Pokedex and you take the boat from Snowpoint city then you can only challange the Battle Frontier, but once you have the National Pokedex you can get to the Resort Area and the Survival Area.
go to snowpoint city talk to the man near a boat and set sail to the other part of the place
you have to complete the sinho pokedex then travel to snowpoint city to go on the boat that will take you to the fight area
go to snowpoint city and go on the boat to the battle tower
its in snowpoint city its in snowpoint city
deep in the snowpoint temple of snowpoint city
You have to travel through mt.coronet to get too snowpoint city.