Boston is a city awash in seafood. Fleets of boats trawl for fresh catches right off its shores, while local restaurants lure diners with the promise of lobsters, cod, chowder and oysters. Even places that don’t specialize in seafood often offer these regional specialties on the menu. With such a flood of choices, navigating your way to the best places to slurp down oysters, enjoy a cod cake or crack open a lobster can seem overwhelming. Here are some of Boston’s top spots to reel in the freshest flavors.