Fish usually takes about 10 minutes to grill for each inch of thickness. Add more time if the fillet is thicker. If you have 2 thinner pieces, grill them for slightly less time.
Salmon is high in omega-3 fatty acids, a nutrient which is thought to reduce the risk of heart disease.
For the safest possible picnic, remember that perishable food should be consumed within two hours (one hour if the outside temperature is over 90°.)