bad dark depression droplets drops fluffy front heaven heavens light low nature peace peaceful pressure shower showers sundskies water whispy alert angry black blue centre cloud cyclone dangerous fierce global hurricane looking up low pressure meteorology rotate rotating science season skies sky spin storm summer swirl system tempest tornado tropical turn twister typhoon violent weather whirlwind wild ACV aerodynamic aerodynamics air air-cushion air-cushion-vehicle air-pressure amphibious craft cushion drive engines fans flexible flexible-skirt flight friction high-air-pressure hovercraft hull hybrid-vessel impeller inflated inflated-skirt low-frictional-force MTV multi-terrain-vehicle multiple-terrain on-board pilot propel propellers rise sightseeing skirt skirted specialised-transport speed stationary surface surfaces thrust tourism tourists transport transporting travel travelling vehicle air-controls amenities bubbling high-volume hot-tub hot-tub-spa hydrotherapeutic-massage hydrotherapy jacuzzi jet-technology jets jetted-whirlpool large-tub low-pressure massage massage-jets outdoor outside pump-system pumps sanitized sanitizing small-pool spa spiraling swirling warm warmed waterfall whirlpool