What is Dri-It®?
Dri-It® is made from Calcium Chloride which is processed with Dri-It's patented methods to achieve its unique characteristics. It is based on the same technology used to protect billions of dollars worth of goods shipped overseas on container vessels every year.

I own a large boat which I plan to store for 4 months in a warehouse with no electricity. What would you recommend to protect my boat?
Our suggested minimum for the average boat that size is 12 pouches (here). Simply put, you cannot put out too many pouches, they won't "over-dry" anything, and working together, they will extend the usage span of the pouches as each has less moisture to absorb. The recommended minimum storage rate is one pouch per 50 cu.ft. (a 5' x 5' x 2' area).
Six double packs (12 pouches) should be good if you might be able to check on your boat during the storage period to see if the pouches are getting saturated and needing replacement anytime. If you would like to be sure you are adequately protected and save money, we also offer Dri-It in bulk packing (same pouches, just minus the retail packaging) with 32 or 64 pouches. Thirty-two pouches would be more than enough for 2 rounds of 12 packages, plus extra pouches to tuck in around your engine, inside cabinets or with life preservers or other gear that may have extra residual moisture or be more prone to rust or mold/mildew issues. Placing pouches underneath the dash/console area will offer the electronics extra protection from moisture accumulation inside there. Pouches being used would only need to be changed out when they become completely gel like and no grit is felt inside. Any unused pouches may be kept for an extended time so long as they remain sealed in their original packaging and are kept in a dry location.
Because of the length of time you will be storing your boat, you may want to consider laying the pouches flat rather than using the adhesive backing. The full pouch weighs over 12 ounces and may start to pull loose from the mounting surface over time. There are more tips at the bottom of the page here.

How long will the pouches last?
This is the hardest question to answer, as there is no firm answer. How long the pouch will last depends on several factors.
* The biggest factor is the initial moisture load of the items or area - how wet is everything at the start? This is a combination of moisture that may be trapped in the items to be protected (carpets, cushions, etc.) and the Relative Humidity of your area, the amount of moisture being held in the air which is partially dependant on temperature.
*The next biggest factor is how often will the protected areas be opened?
* The third main factor is how air-tight/water-tight is the area you are wanting to protect?

For long term protection, the best solution is to periodically check the pouches and replace saturated ones with new ones. The pouches put in later will last longer as the initial moisture load was absorbed by the first pouches, so less excess moisture is needed to be removed by the later pouches. Then they will simply have to absorb any new moisture that seeps into the protected areas.
If the protected area is opened frequently, the pouches will become saturated more quickly as fresh moisture is allowed back into the area each time it is opened. If the protected space has a good seal that makes it very air-tight and water-tight, the pouches will also last longer as there is less chance of moisture seeping back into the area.

Does it make a difference what temperature the storage area is at?
Dri-It is made to absorb water vapor and does not work as effectively at temperatures getting close to freezing; and is not designed for temperatures over 150°F. What really makes a difference is the temperature swings you have where the protected area is, and what your area's normal relative humidity levels are. This is relevant because your area's normal relative humidity will have an affect on the initial moisture load, and warm daytime and cold nighttime temperatures can cause an increase in chances of condensation forming on surfaces before all the excess moisture is fully contained. In the shipping industry this is commonly called container rain and can actually cause water to condense on many items, or run down walls and other items and drip onto your belongings.