Here's a great way to cook up fresh tuna, and its easy, too!
All you need is some marinade, bacon, toothpicks soaked in water, some foil, and BBQ sauce.
Guarenteed to be a hit.
Soak the tuna loin in marinade for however long you want.
Then, using the wet toothpicks (so they don't burn in the BBQ) to hold the bacon in place, wrap bacon around the tuna loin, completely covering the fish.
Finally, BBQ until you are happy that the fish is done. 350*F is a good temp, and don't overcook.
Use foil to catch all the oil - tuna is very rich and there will be alot of oil!
Also, BBQ the fish while cooking the crab you just caught - highly recommended as a side dish.
Finally, tell everyone that the fish will be done in 1/2 hour, and hide in the bathroom with the shower running - the water will drown our the noise of your lip-smacking and crab munching.
And it will help clean up the BBQ sauce all over you.
No advice on what to tell the hungry family when the fish is gone - they won't believe anything you say.