Three guys, one Irish, one English, and one Scottish, are
out walking along the beach together one day. They come
across a lantern and a Genie pops out of it.  "I will
give you each one wish, that's three wishes in total",
says the Genie.

The Scottish guy says,  "I am a fisherman, my Dad's a
fisherman, his Dad was a fisherman and my son will be one
too. I want all the oceans full of fish for all eternity."

So, with a blink of the Genie's eye FOOM! the oceans were
teaming with fish.

The Irishman was amazed, so he said,  "I want a wall around
Ireland, protecting her, so that no one will get in for all
eternity."

Again, with a blink of the Genie's eye POOF! there was a huge
wall around Ireland.

The Englishman asks,  "I'm very curious. Please tell me more
about this wall."

The Genie explains,  "well, it's about 150 feet high, 50 feet
thick, protecting Ireland so that nothing can get in or out."

The Englishman says,  "Fill it up with water."