Perfect grilled fish?

[Tigerrr]

What are the secrets to perfection in grilling fish? We had various grilled fishes in Italy recently and they were all perfect - firm flash and delightful crisp skin both sides, easy to take off the bones etc.
I have often tried to grill fish at home and I cant get the same results. So here are some questions for fish grillers? (strictly referring to flatfish or white sea fish not trouts or sharks etc.
Skin on or off - most of my books say off but charred shin is a delight
How do you get charred skin both sides - this never quite works for me
How do you get charred skin and not over cook the fish
How to tell when a fish is at that perfection of being cooked precisely without being overcooked or still a bit underdone

Plus any other grilling tips.

[fred the great]

Can't help myself but would also like to know how to do it.

The tasteofhome website has some examples and  other places came up when I did a quick search.

[hubner]

I suspect you'd need a high temperature for a relativley short time with oil brushed onto the skin, so put the fish nearer the flame.

[FatBloke]

First thing. Hot grill or barbecue. If barbecue, oil the grill first.
Second, leave the skin on but scale the fish, that way you get lovely tasty crispy skin, and the skin keeps the moisture in and holds it all together.
Depending on the thickness, if you're grilling fillets, you need only grill the skin side, the other side will still cook but will remain succulent. If they are thick fillets give them a quick blast on the flesh side, then turn them over to cook the skin side.

It only takes a couple of minutes to grill a piece of fish. If you're not sure it's done, stick a sharp knife in to see. Nothing is worse than overcooked fish.

Serve skin side up.