Tiny air bubbles on colloid surfaces. Thought to reduce drag, such as would be of benefit to swimmers wearing a suit coverd in them. See first images of nanobubbles

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An ultra-fine gas bubble of diameter less than 1?M (1?M=1/1,000,000 m). It usually occurs temporarily in the process of shrinking a micro-bubble, but disappears soon because of its physical lability (constant change). Recently scientists have succeeded in producing stabilized nano-bubbles by collapsing micro-bubbles instantaneously in water containing electrolyte ions.

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Tiny air bubbles on colloid surfaces. Thought to reduce drag, such as would be of benefit to swimmers wearing a suit coverd in them.

Source

An ultra-fine gas bubble of diameter less than 1µm (1µm=1/1,000,000 m). It usually occurs temporarily in the process of shrinking a micro-bubble, but disappears soon because of its physical lability (constant change). Recently scientists have succeeded in producing stabilized nano-bubbles by collapsing micro-bubbles instantaneously in water containing electrolyte ions.

Source