I have used Pelican cases for over 20 years and on multi-week canoe trips at times. Mine have been floating with no damage to equipment inside.
When "in use" I tend to have the case in front of me on the floor of the canoe or on the packs with the lid unlatched, but closed, to keep out splashes, and then just open the lid for access. I do a lot of canoeing, and have no fear of tipping over in flat water, even with good waves, but splashing is always a possibility in a canoe. If you are not using the camera, just latch the lid and nothing will harm your stuff.
I have tried plastic bags, "dry bags", backpacks, camera bags, wrapping in rain gear, and none work as well as a decent sized Pelican case for ease of access, and absolutely nothing protects it better when the case is shut tight.