Excellent Choice for the Price
This ~$40 Rumpumpack had strap pockets that fit my phone, side bottle pockets that will fit larger bottles, two large compartments (one of which is insulated for the included bladder if you want to use it), a medium size compartment that has a zippered interior pocket, an open smallish compartment (would fit water shoes), and a small exterior zipper pocket.  There are d-rings for carabinders on each strap as well as a couple other possible loops on the front. The back padding might not keep it off your back as you like, but I'm willing to try it.  I've looked at many more expensive backpacks that have fewer desired features.
Rating: 5 stars