Quick pole. Should I buy a waterproof pack cover for the backpack that I already own so my gear does not get wet in the canoe, OR by a dry pack like the sealine or cabelas brands.

what sort of pack do you want to cover??

I have the rei mars 85 pack will be using for backpacking. I would put the pack in the canoe with the straps facing the sky so that any water in the bottom of the canoe does not seep into the pack and get all of my gear wet. OR as I mentioned earlier I might get a dry pack.
I just dont know what would work best.

waterproof the pack from the inside. 3-4 mil contractor garbage bags work great for liners.

So Kanoes, does this advice make you an innie x 2?

Agree with kanoes-get thick mil contractor bags at fleet farm or menards and put them inside the pack with your gear inside the bags. Maybe double bag if you are nervous or bring a second bag along in case you break through. This will waterprrof the insides just fine.

A single bag can last mulitple trips, but even if they don't they are relatively cheap and can be used for trash at home after the trip.

For what it's worth, Ziploc makes some huge zip locking bags--I think they're like 24" x 36" (you can buy them at Gander Mountain) and I've used them in the past to keep gear dry. I like the fact that they seal at the top and can be used multiple times. Here's a link to Ziploc's web site: Ziploc. Right now you can print a $3 off coupon for these from their web site (and no I don't work for SC Johnson).

I agree to waterproof that pack from the inside. If you put a raincover on it and place it straps up in the canoe you will be protected from the water that may be in the canoe but will be collecting water from the sky if it rains.

If you do get a dry bag pack, get one with the best suspension and hip belt.

I line the inside of my Duluth "old style" food packs with contractors plastic bags. There is no second guessing when it comes to my sleeping bags and warm clothes. They go in dry bags.

I use NRS 3.8 Heavy-Duty Bill's Bags ($79.95). These bags are hell for stout with heavy duty bottoms. The packs have been tossed on rocks and fully drenched. They are excellent on the back and pack flat gunnel to gunnel in the canoe..... works for me.

Check out NRS bags at NRS

"waterproof that pack from the inside" is the best way to go for a canoe trip. I have used pack liner bags in the past but this year tried something different. I used 20/25 liter roll top 'Sea-Line' waterproof bags, 2 of them hold my clothes and sleeping bag [in a compression sack, and gear needed to stay dry. There is room for 3 in my 'Woods Mason' bag. This system worked very well in the rain last Sept.

butthead

Ditto Butthead. You can also see where and whats in your sea- line bags.

I second thlipsis on the big ziplocs. I bought some at Gander Mountain. There were several sizes in the package, from big to bigger. They're a much heavier gauge plastic than the ziploc sandwich or freezer bags. I've used the same ones on three trips. Some of the zips have started to tear, but they're pretty inexpensive.

I did the covers once. Not worth it. Do it from the inside with a bag.