If the river is 50 feet across i.e about 15 metres then diving to the centre of the river in your speedos (15 feet is deep enough) should be doable from a raised embankment or platform and should get you about 30-40 feet across before resurfacing. (if you can do a pool length 25m underwater) Your gear will be rolled up in your waterproof jacket tied to your one of your feet with the paracord. You should be able to get to the other side within about 30 seconds. You can then pull your bundle across once you have made it to the other side. Dry off and get clothed again (dry clothes wrapped in the waterproof bundle) and build an emergency fire to ward off potential hypothermia.

It won't be a very pleasant swim and could be potentially dangerous and life threating resulting in grim reaper deciding its your turn, but should be doable. As always practice will help.

Broughty Ferry Dook

Edit: Make sure that you bring your knife (around you neck) with you in case you have to cut the paracord if it gets snagged and is unrecoverable.