I bought one of these to use in my sunfish to carry things like a towel and my cell phones while i was off exploring different beaches on the lake. unfortunately the bottom of the bag didn't hold up well to the sand in the bottom of my boat, cause several small tears that resulted in the soaking of my phone and towel. if you want something really tough, this isn't it.
I have several Sea to Summit dry sacks, in various sizes, and they're incredible to use for dry sacks while kayaking! Absolutely nothing ever gets wet when I use these sacks, and they are so durable! I have also used them in luggage when traveling and have found that I have no worries about anything leaking in my luggage. These are wonderful sacks, and they are very sturdy and extremely waterproof! I love the blue color as well!
This is an awesome product. I have the small bag for keeping items like cell phones, cameras, and keys safe and dry. It's great for when your canoe tips, spilling all your things into the water.