If you're in a tube instead of a kickboat with oars, tides & currents can be a problem. I tried tubing Sandmound Slough once - big mistake. Also tried kicking out in Middle River near I think it's called Turner Cut - way too much current. Lots of places, though, are no problem. Discovery Bay, Big Break, Rock, Piper, Whiskey & Trapper Sloughs are all tubable. The Delta is a lot of fun & is a great place to fish. Good luck.