Peel shrimp, leaving tails on; devein, if desired.
Coat 12-inch metal skewers with cooking spray. Alternately thread shrimp, grouper, salmon, snow peas, bell pepper, and pineapple on skewers. Place kebabs in a shallow dish.
Combine lime rind and next 7 ingredients in a small bowl; pour over kebabs. Cover and marinate in refrigerator 1 hour, turning occasionally.
Remove kebabs from marinade. Grill, with lid closed, over medium-high heat (350° to 400°) 6 to 7 minutes on each side or until fish flakes with a fork. (During grilling, baste occasionally with marinade.)
Garnish, if desired. Serve immediately.