Earlier this Spring, Beloved Wife attended a conference in Portsmouth, New Hampshire, and NatureBoy and I tagged along. While BW was conferring, the boy and I ourselves busy. In the evenings, we ate out and explored some of the shops in Portsmouth downtown.
One of the things NatureBoy and I did was visit the USS Albacore submarine museum, which comprises a small gift shop and museum, and a self-guided tour of the actual submarine.
The Albacore has two large, offset rudders and twin, counter-rotating propellers for increased speed and power.