U-HEBLIL: A blue-laser LiDAR system enabling high-resolution underwater imaging at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si120.svg"> <mml:mn>15.53</mml:mn> <mml:mi>A</mml:mi> <mml:mi>L</mml:mi> <mml:mi>s</mml:mi> </mml:math> in ocean turbulence environment