I am old, not skinny, but not fat and don't have much trouble.
The freeboard of the Wave is lower toward the stern of the boat. I work my way back there where I can reach the hiking strap with a little effort and from there I can get on the boat pretty easily.
The other way, if I am quick enough, is to jump on the lower hull as the boat is about half way righting. Once I know it will continue to right itself, I wrap my legs around the lower hull and try to grab the front beam.
once the boat is righted you are about half way on the boat.
Also, if you have a bow spreader bar that is one more piece of equipment that you can use to get a leg up.
Good luck,
Rick