Depth of field and focus are OK.  The out of focus region is OK (except perhaps the spare mid pressure hose tied up over Marty's left shoulder).  What is Marty doing?  I'm pretty sure this is surface BCD remove and replace (use you right hand to grab the tank valve and then sit on the tank butt.)

Date:	Saturday, July 25th, 1998
Film:	Fuji Nexia APS 100 (print)
Lens:	105mm f/2.8D AF Micro-Nikkor