20 Master Angler speed question

[wildlifeone]

I have a 78 master angler 20 w/ a 200hp mercury1988). I only get about 43 mph wot. and the boat runs very flat in the water. I have tried different props to get lift but no luck. I was thinking maybe the hull had develpoped a slight hook in it may be due to poor support of the transom. are the bottoms absolutl flat .Will a straight edge give me my answer??? The motor has good compression and is ok