Here's a recent adaptation...

I should explain, for my American friends, that "rock" is a kind of hard candy, shaped like a peppermint stick (but not necessarily peppermint in flavor), commonly sold to tourists in seaside resorts. I couldn't find a photo of chalets, as I know them, but click here for something close.

Copied from http://www27.brinkster.com/skarmony/DreadRock.html

DREAD ROCK
(Judge Dread a.k.a. Alex Hughes)

When I go down the seaside, I'm feeling rather rude.
The girls in their bikinis are showing all their boobs.
But when they see my stick of rock, they all shout out with glee,
"Before you give it all away, please save a length for me!

"Oh, ho, ho, oh, what a big one! I've never seen one as big as that before!
Oh, ho, ho, oh, what a big one! It must be fourteen inches long or more!"

I took a stroll along the beach. My rock was in my hand.
I saw a girl who was buried up to her neck in sand.
She said, "Some boys did this to me. Please help get me out,"
But before I could assist her, my rock shot in her mouth!

And she cried, "Oh, what a big one! I've never seen one as big as that before!
Oh, ho, ho, oh, what a big one! It must be fourteen inches long or more!"

Now I'm always in the discos as soon as the sun goes down.
I chat up all the nice girls with bodies nice and brown.
I take 'em back to me chalet and they always get a shock,
For when I turn the lights on, and they see the size of me rock!

They all cry, "Oh, what a big one! I've never seen one as big as that before!
Oh, ho, ho, oh, what a big one! It must be fourteen inches long or more!"

Now me holidays are over. Me rock goes home with me.
Although it's not as big as it was, it's big enough for me.
If you want to know who my girlfriend is, take a look around the place.
She's the one in the corner, with a smile upon her face!

'Cos she knows that it's a big one! She's never seen one as big as that before!
Oh, my God! Oh, what a big one! It must be fourteen inches long or more!