Old Walter the Whale is a whopper,
He's as big and as blue as can be,
And if he don't eat you up for his supper,
He'll gobble you up for his tea.

I have no idea where it can from or why I know it, I just have vague recollections of singing it when very young.

And there's also the fab
"40 years on an iceberg out in the ocean wide,
Nothing to wear but pyjamas, nothing to do but slide,
The weather was cold and frosty,
The frost began to bite,
I had to cuddle a polar bear to keep me warm at night!"
not particularly ocean-linked but it does use the word!