Sea&Sea DX Macro Port Base @inonadmount An action camera is a

An action camera is a deep focus camera which does not require focusing but prevents a subject gets in focus in close range (within 60cm/2ft range in theory for GoPro® camera) thus not usable for underwater macro shooting

When taking underwater photography or video

You can choose from 12 different diameters ranging from 2mm to 24mm

(*) Average time to get half brightness comparing to initial performance when using eneloop pro batteries (Model code: BK-3HCD)

Sea&Sea DX Macro Port Base @inonadmount An action camera is aThe DX Macro Port Base goes in between the housing and the port. The port base and DX Macro Port 50 II are small and specifically shaped to enable positioning in tight areas where small subjects might be hiding.