Ignore the wise ass responses. These types of boats have a very low center of gravity (your own weight acts as an axel) on which the boat rotates as you attempt to paddle. Often it requires two people rowing to have it move forward successfully
Challenger is slightly smaller and three pounds lighter. It also rolls up a lot easier due to not having pole holders. The PVC material is the same thickness. If you plan on carrying this any distance get the challenger. If you weigh 250+ get the Seahawk.
Hi;I have a 55-60 lb. dog and getting her in is no problem. What I find helpful tho is putting a tarp or cutting an air mattress the length of the boat. The added protection helps keep toenail pokes and scratches from getting to the raft itself.
You'll need a pretty big bag to fit this boat in. Intex sells them on their website if your interested. Ive hiked carrying this thing (deflated) for about a half a mile no problem. I don't recommend carrying it more than that though it can get heavy sometimes. But the bag is easier.