If you are boiling prawns or shrimps as the case may be, two minutes is all you need. That is - two minutes. Then plunge them onto ice.
On the barbie- no more. They will be rubbery otherwise… :o
Years ago I saw a visiting musician (I had no idea who he was other than that he was African American) guesting on a cooking show. He was showing his recipe for Garlic and Chili Shrimp. It was basically what Ukulele Ike recommends but then they were dredged in a bowl of chopped garlic and chili before shallow frying. I have stolen the recipe and varied it lots of ways and they are all fantastic. The flavourings bake on to the prawns and provide a crunchy coating. Crushed peanut and chili works, ginger and coriander works, lemon rind and crushed macadamias works…even curry powder and desiccated coconut is good. But the trick is the marinating in the ziplock bag. One hour is far too long if they are small though…the lemon juice will half cook them.
Ginger? You’d be surprised how difficult it is to get little bits of flesh-colored vinyl out of one’s teeth. Still, I found that dish to be surprisingly filling. 
This recipe, with lemons and everything else fine and delish, I must try this.
Silentgoldfish, no sweat. When I get to Australia in the next few months, you can teach me the proper way to cook Prawns? Yes? 
Ike…Ike…Ike…. My friend, you’ve developed a hell of a finely-tuned palate for a guy who used to subsist entirely on Junior’s Cheesecake.
Was it perhaps a novel by Tony Aspler ?
Shrimp on the Barbie
That’s a horrible thing to say about Ken!!