How do you find the key to the door in the hidden lake on club penguin?

On the first level of puffle rescue (the black puffle) follow the squid shadow and he will spurt out bubbles. Get the bubbles so you stay alive. then he leads you to this place where u can walk and swim. Go all the way in the end of the passegeway to find a little square. Click the square and your in the underwater room! But be sure to remember to get the moss key pin to come back in the room any time with out doing the whole thing over agian

your welcome for helping

and i hope it helped you!

your truly-

dch1234545