how does camping outside in rainy weather becomes unpleasent

Camping outside in rainy weather is unpleasant because everything in the boat becomes damp. You're soaked, the boat has water, the tent is wet and heavy, and "Rainwater is the chief article of diet at supper. The bread is two-thirds rainwater, the beefsteak-pie is exceedingly rich in it, and the jam, and the butter, and the salt, and the coffee have all combined with it to make soup." This is compounded by being unable to smoke because your tobacco is too damp to light.