The old dockyards on the outskirts of Fuzhou are worth a visit for naval or history buffs. They host old ships like a frigate from the 1940s. For 30RMB ($4.50), you can visit a museum that memorializes the Battle of Majiang and stroll around the outdoor gardens, where you'll find large defense guns and the old British consul. There's also a free Chinese naval museum with a cool statue of a seaplane outside.
You can take a taxi or bus 131 or 73. The bus takes more than 40 minutes but only costs 1RMB, and the scenery is beautiful.