I mean.... this doesnt look terrible. I dont know what any of this is, or how much area is done here, or why this step is needed to make a boat but I am assuming you made the tallest cut, moved the blade down, moved the board over a bit, turned saw on and repeated opposite direction to get next step down and repeated 27 times (it looks like), creating a ladder step down effect? Thats how Im interpreting these pictures right? I think this is exactly how I would do this. My only worry would be sliding the board back and forth so many times, getting thinner and thinner and it wanting to crumble from the weight. how thick was the sheet of wood? 3/4" and how much do you move the blade when making the next cut?