Possible Clues:

• Having had some smoking they are taking a nap
• That's what smoking will make of her rings
• They're not awake to the fact that that can result from smoking?
• Having gone in for smoking, they're now completely cured
• Captain initially going East for fish
• Smoked herrings for skipper
• They've dropped off the food
• Seems they have a little sleep and they're cured
• With a little sleep they're cured, but it's all very fishy
• A little sleep will cure them - very fishy