A couple days ago I went with a few friends to the Salt River to go tubing. It was my first time and I learned several tips on how to be safe:
1) Go with a couple people. They will help remind you to do things, like put on sunscreen. Also, they can help you paddle in the right direction when there is a strong current.
2) Use spray-on sunscreen (85 SPF) and a sunscreen stick for your face. I used both and I barely got burned.
3) Remember to apply before going in the water, 30 minutes after getting in and every hour after that. I followed this mostly religiously and didn't get burned, except for a couple small places.
4) Don't go in the water too often or apply sunscreen again right after you get back in your tube. My friend went in the water a lot and ended up getting badly burned.
5) Bring a hat. I couldn't find my hat so I didn't wear it and ended up getting burned on my scalp. It is really itchy and irritating at the moment...
6) Bring water shoes. I only brought flip flops and it was really painful to walk on the rocks until it was shallow enough to put on my flip flops. Also, in case there is something sharp in the water, water shoes are safer to wear than going barefoot.
7) Bring lots of water and snacks. There is no shade, except under the trees at the side of the river (where snakes supposedly linger). Therefore, you need to remember to bring tons of cold water to stay hydrated and prevent heat stroke. Also, a few snacks and lunch will sound good, especially if you take the longer routes.
8) Bring an extra shirt. If you start to feel really burnt, a light t-shirt will save you from the sun a little.
9) Wear a one-piece bathing suit for more protection. I wore a one-piece bathing suit and shorts to save myself from any unwanted sun.
10) Bring an umbrella if you can. I didn't bring one, but that would definitely improve the not-getting-burned situation.
11) Remember to bring a cooler and an extra tube hold the cooler and other belongings. When I went, my friends brought a cooler and three extra tubes (two small ones and one big one for the cooler), to carry food, drinks and personal belongings. This definitely made the experience more enjoyable.
12) Tie your tubes together in the water. Although there are signs saying you shouldn't tie your tubes together, it is more enjoyable this way and there really is no safety issue. However, I don't advise tying tubes together if there is more than five people, since it might get tricky to fit through small river openings.
13) When coming up on a split in the river, paddle in advance. From experience, the current can be pretty strong at times and, if you don't paddle more in advance, it can carry you to the wrong side.
14) Follow the screams. From my experience, the parts of the river with the most screams were the best! These had stronger currents and splashed me and my friends. If you don't like getting splashed and freaking out, then I would suggest going the other route...
15) Bring a waterproof radio. I regretted not bringing a radio because at times there were long stretches and music would have been more fun.
16) Bring towels. Cover your tubes with towels because only black tubes are rented out and those things get HOT. If not, you have to constantly splash your tube to avoid getting burned.
17) Remember to spray your feet with sunscreen. I think a lot of people forget this area and thankfully I didn't.
18) Set a timer if you think you'll forget to reapply your sunscreen. My friends usually reminded me and I could generally tell when I needed to reapply, but setting a timer is also a good option.
19) Bring sandwich baggies. These are useful for keeping cell phones, cameras, keys, etc. dry.
20) Remember to bring cash. It costs $15 in cash for a tube and bus ride. Also, snacks and souvenir t-shirts can only be purchased with cash. Bring about $40 in cash, just in case.
I think that is everything you need to know about staying safe while tubing. I would definitely suggest going to the Salt River for tubing because it is beautiful and lots of fun! On my trip I saw a couple horses at the side of the river, a heron and a beautiful black and red bird. It is relaxing and a great way to spend the day. However, you may get pretty sleepy afterward, since the sun can be draining (especially after the long routes).
Stay safe and have fun!