...anyone had any luck making nice with a local "commercial fisherman" down at the marina and get them to take them out in their panga and trade a couple of the day's catch for a case of beer?...
Be serious!
The airport is near the old marina, which is my favorite place to stay, and which has a couple excellent restaurants. But you might want to try to charter a panga out of Punta de Mita, which is in Nyarit, not Jalisco, where Marina Vallarta is located. Most of the sight seeing and shopping will be found in town south of old Marina Vallarta, not north, where Nuevo Vallarta is located. Casa de Tequila is worth seeking out, in town. And for a very special dinner have a cab take you to La Chosa, in Mismaloya, just south of town.
