Three Wishes and a Wall

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 Englishman was amazed, so he said:

- I want a wall around England, 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 England.

The Irishman 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 England so that nothing can get in or out.

The Irishman says:

- Fill it up with water.