Heavy duty dry bag vs Liner for backpack while packrafting

Even a waterproof pack like the Porter (which I have) will still need waterproof protection for your “dry goods” while packrafting, because of the limitations of the roll top closure while submerged. For a pack liner, it’s more of the closure type that will matter, than how “heavy duty” it is (unless you puncture it of course). The better it holds air, the better it will keep water out. I use a lightweight (30D) pack liner all the way up to class 4, but I make sure it’s sealed properly and I only use it for soft items. Pot, trekking poles, etc I keep separately. If your critical insulation and electronics are in a dry bag, I don’t see why a heavier pack liner is needed. For class 2, I don’t use a liner at all, because if my insulation is dry there is nothing else I carry that can’t get wet.

I think I used that same dry bag a few years ago. Should work but like Ben said check the closure. Mine leaked there a bit once because I didn’t roll it tight enough.

By the way I don’t think the Catalyst is a bad packraft pack. It won’t dry quit as fast but that’s the only real downside I can think of.

Until you flip the demands of packrafting on waterproofing are fairly modest.  If you’re paranoid, the Sealline Nimbus is the lightest submersion-proof bag I’ve used.