Designed this mount for my JBL Go 3 to mount on my Sea Doo Fish Pro Scout in the LinQ mounts on the left and right. It prints in 4 separate parts. It can be printed without supports.
I printed with supports just to print a little cleaner.

Could use the LinQ clip and Backmount brackets to design around to hold other items. This holds it pretty securely. I used a velcro cable management 'zip tie' to hold the lid down. Tried a pressure clip for the top, but it broke rather quickly due to the limited size I had to make to still fit the speaker.

Tested this on a day, on a brackish river down to the harbor, with a fair amount of wind, current, and waves. I was battling 2-4 ft swells for a number of hours. Needless to say the Ski was getting tossed around a bit. Fairly rough ride. Held in place wonderfully. No signs of coming loose or breaking.

Additional parts I used:
-1 x 30 mm Aluminum M5 spacer ( OD is 10mm )
-1 x 60 mm Panhead M5 screw
-1 x M5 nyloc nut
-2 x M5 washer
-1 Velcro cable management tie ( to secure the lid )

• bit of superglue to put everything together

Included a picture of the back mount dimension drawing so that you could design a mount for your own projects that would use this mount and LinQ clip to secure it to your PWC.