GTA3 Tunnel Glitch (ps2)

How to get through the tunnel early in the game, it lets you access the 2 islands still blocked at the beginning of the game. This way you can go ahead an do the Vigilante an Firetruck missions, so you'll have 6-bribes an a flamethrower at each hideout. The same glitch also works to get back to Portland from Staunton Island