Unless I'm walking around with my camera, I actually take the strap off it because it's caused more problems, catching on things etc, making me lose my grip on the barrel. From my construction days, I got very used to only picking up equipment once you've got a strong grip on it. The only time ever dropped something was when the strap on my 990 caught on my seatbelt buckle and the camera went flying onto a concrete floor. Nikon nicely rescued me from that disaster.
Glad to see you relaxing and enjoying yourself, Patrick. With all the equipment I need for kayaking, I actually have made myself a list to check before going out the door. Believe it or not, I once got all my gear, drove to the put-in spot on Lake Ontario, got the kayak off the truck, all loaded with gear, dragged it to the water's edge and then realized - FORGOT MY PADDLE!!!! Had to reload all of it back on/in truck, drive for 2 mins to get the paddle and do it all over again. Take right hand, turn palm upwards, soundly smack self on forehead and vow to never do it again. And I didn't even have diapers and small kids to blame it on!! *LOL*
Steve, looks like it's one of those rail focusing thingies, for very fine-tuned focusing.