An insulating device can include an aperture having a waterproof closure which allows access to the chamber within the insulating device. The closure can help prevent any fluid leakage into and out of the insulating device if the insulating device is overturned or in any configuration other than upright. The closure may also prevent any fluid from permeating into the chamber if the insulating device is exposed to precipitation, other fluid, or submersed under water. This construction results in an insulating chamber that is substantially impervious to water and other liquids when the closure is sealed.