HELP! MGS3 Hornet Camo

[Buckaroo Banzai]

Okay, I defeated The Pain with the Mk22, and there's a case (which I believe
is the Hornet camo) on the island he was at, but I can't get on the island
to collect the camo. Please tell me what I'm doing wrong!

Thanks in advance!

[Tek]

Swim out to where you would normall leave the area and proceed. Before
you go through the tunnel, along the wall, there is a ledge to walk on.
Walk on the ledge all around the area (you end up walking towards the
screen) and you get to an edge. Once there, you can jump off and land
on the island where the pain was.