Basically, inflatables are quite easy to take care of. The boats can be stored either inflated or deflated (see note below), but should be kept out of the weather.
Additionally, it is best to store your boat after it has been cleaned & the PVC (or hypalon) has been treated with an appropriate protectant.
See our 5 step process below:
1. Clean the boat well with fresh water & an inflatable-compatible soap (Mary Kate Inflatable boat Cleaner is a good one). If your boat has an air deck or aluminum panel floor, it is worth taking the floor out & cleaning underneath the floor (remove sand, leaves, etc)
2. Give the boat a good looking over for signs of wear, fabric tears, etc. If you think there a areas that might eventually lead to an air leak, mark them for repair in the spring (glues need warmer weather to set-up well)
3. Apply a UV protectant such as 303 Aerospace Protectant to keep the tube fabric pliant and lubricated.
4. Cover the boat, or keep it indoors. NOTE: do NOT deflate if your storage area is likely to have mice, squirrels, etc (they will eat the fabric)
5. In the spring, make sure tubes are inflated to the proper pressure before using the boat. Proper inflation is 3-5psi. The means the boat will deflect slightly (1/8" or so) if you push the fabric in with your finger. DO NOT OVERINFLATE BOAT or leave in a place where the tubes will overpressure (i.e. in a blacktop driveway on a hot summer day).