Collect 10, and you can get the bulletproof vest.
Collect 20 and you'll get a chainsaw.
Collect 30 and you will get a revolver.
Collect 40 and you will get a flame thrower.
Collect 50 and you will get a sniper rifle.
Collect 60 and you'll get a revolver machine gun.
Collect 70 and you will get a rocket launcher.
The above will appear in the original storage point of the hotel, the mansion on Starfish Island, and the roof of the apartment near the West Island Stadium. There are helicopters on the tarmac on the roof all the year round.
Collect 80 and you can get a water helicopter behind the mansion in Central Island.
Collect 90 and you will get tanks.
Collect 100 to get Apache.
The above will appear in the military camp in the north of West Island Airport. Don't forget to change your uniform when you go.
After Apache mission completion 100%, it is also available all the year round on an apron near point C at the southernmost tip of East Island!