It depends. Dock users tend to want to leave a Nettle Net Boat Pool in the water longer than boat users. How long you can leave it in depends in part on how quickly algae and other organisms will grow on the pool at your location. Usually a weekend is fine, but longer than a few days may result in algae starting to grow on the pool. To learn how long you can leave it in, simply retrieve the pool and inspect it periodically. If you are concerend, fully retrieve it and rinse it before redeploying it. Under any circumstances, do not leave the pool in the water in inclement weather or high winds, as these conditions could damage the pool.