Rescuing the Brothers overlaps with the Sea Monkees Quest, the main storyline of undersea adventuring.
Text
Initial Visit:
Hello there, young Adventurer. Back when I was your age, I used to be quite a fisherman. These days, well, what with my arthritis, and my gout, and this old war injury, well, I don't get out there so much anymore.
Say, is that a set of SCUBA gear you've got there? Maybe you can help me. I lost my favorite boot, you see. Dropped it right off the side of my boat. Time was I'd just fish until I dredged it back up, and boy, lemme tell you, was it a hoot! But not anymore. That dang marlin sapped the last of my strength.
Think you could go down there and get it for me? I'd be obliged, yessirree.
Oh, and hey, if you wanna take your little buddy with you, this'll help.
The Old Man takes his boot and gives you your reward.
You acquire... something. [[Data:{{{item}}}]]
"Take care of yourself, Adventurer. If you need me, I'll just be sitting here, dreaming about lions."
Subsequent visits after trading:
The old man snores fitfully, muttering something about a lion. Dying. In the rain.
References
Much of the Old Man's text refers to the Hemingway novel The Old Man and the Sea. Specifically, the line "I'm off to dream about lions" refers to the character Santiago and his dreams of watching lions frolicking on the beach.