Level 4 - Angler's Tunnel quadrant C4 is complete.
Level 4 - Angler's Tunnel quadrant D4 is complete.
Level 4 - Angler's Tunnel quadrant D5 is complete.
Level 4 - Angler's Tunnel quadrant C5 is complete.
One thing to notice, this room is one of the few that will physically change depending on whether you are in DX or Classic mode, as seen below
As you can see, in the Classic version there are two extra spaces of shallow water. Why are these spaces absent in the DX version? Because they allow you to do a running jump up to that door way in the upper left hand corner which would let you use a key before you were supposed to, the only way to get the next key is with the flippers, and the only way to get the flippers is with the next key, so your kinda boned. Nintendo fixed this in the DX release.
As I have said earlier, the Classic mode will have more glitches then the DX mode.
Level 4 - Angler's Tunnel quadrant B5 is complete.