Yet another vaguely remembered movie!

I remember watching this movie when I was very young, and I'm fairly certain of the dates in the title. I don't really remember much about plot, characters, etc. except that what little I do remember all took place underwater. I think the main character was a little boy.

The one thing I remember clearly is a snippet of a song. The lyrics I remember (and I'm sure the spelling's off, as Google searching got me nothing) are as follows:

"Hi, hi, hi, hi, hi cockle loren; hey, hey, hey we're on our way!"

This song has gotten stuck in my head a couple of times a year for several years now. I know this isn't much to go on, but if anyone could help I would greatly appreciate it. I just finished spending several hours searching's entire list of animated movies (some 26000+ titles) hoping one of the titles would jog my memory. Needless to say, I was disappointed after finishing the "Z" section.

Thanks in advance!