Bay seniors who are contemplating downsizing might want to visit the USS Pampanito docked in Pier 45 near Fisherman’s Wharf. It’s a battle proven World War II submarine that saw action throughout the Pacific, sinking at least six enemy ships. It’s hard to believe as you inch through the tiny spaces under the deck that 80 men once called this home. If you’re not claustrophobic ask about their overnight programs.Everything has been thoroughly restored. Opens daily at 9. Adult $12. Children $6. And like any bona fide National Landmark it comes with its own gift shop.