Dry bags are fine but a pack liner is king

Use a heavy-duty pack liner (like a trash compactor bag) as the first line of defense, then put your stuff in dry bags inside that.

The problem with dry bags alone is they rely on the seal staying perfect. River crossings involve dunking, pressure, and sometimes the bag getting twisted. A single pinhole or a poorly rolled top and your sleeping bag is wet. A pack liner is simple redundancy: even if water gets into your pack, the liner keeps your gear dry.

Here’s what actually works: line your entire pack with a thick trash compactor bag (not a kitchen bag — get the 2-3 mil ones). Then pack your sleeping bag and spare clothes into a separate dry bag inside that liner. Your tent can go loose in the liner since it can handle some moisture. For river crossings, take your pack off and either float it across in a dry bag or carry it high above your head. If you have to keep it on, loosen the straps so any water pressure doesn’t pin you down, and make sure the liner’s closure is twisted tight and tucked under the pack’s top flap.

One extra tip: keep your sleeping bag and change of clothes in a dedicated lightweight dry bag (like a Sea to Summit or similar) no matter what. That’s your “everything went wrong” insurance. The pack liner handles the splash, the dry bag handles the dunk.

Future you will be very happy to have a dry sleeping bag.