I have a 1972 18 ft aluminum deep v starcraft boat with a 2011 60 horse Mercury four stroke on it. I bought it a couple years ago and I would like some information on changing the prop. I have no idea about prop sizes and prop pitches and any information would help. The prop is a stainless steel prop but it seems very small to me. I measured it across and it's a tad under 10 in if I am measuring correctly. With me and one other person in the boat I can get it up to about 36 mph but it takes a while to get there. If I put four people in that boat it will hardly plane out and I can only get 16 to 18 mph. 36 mph is great but I would rather have more low end and be able to haul more people. Also I have a very tough time pulling a tube. I am wondering if I could go with a bigger prop or a pitch change to get more low end out of it. I don't know how to tell what pitch my prop is. I appreciate any and all suggestions thank you