US Patent 11548601 Multi-chamber inflatable device

A flotation device that can include a multi-chamber flotation element having an active inflation chamber and a passive inflation chamber. The flotation device can have a first valve in fluid communication with the active inflation chamber but not the passive inflation chamber and an opening in fluid communication with the passive inflation chamber but not the active air chamber. The active inflation chamber can be configured to be inflated through the first valve. The active inflation chamber can be configured to expand the passive inflation chamber from a collapsed state to an expanded state as the active inflation chamber is expanded by, for example and without limitation, permitting ambient air to enter the passive inflation chamber when a pressure within the passive inflation chamber is less than an ambient air pressure.