The Shark was my first boat and they all had them. I was Class Sec. for year and lobbied heavily against them.
Spray Rail was the name of them, and they lived up to their name. They sprayed water everywhere and really got you wet.
One Class Pres. who was for keeping them said they helped keep the boat from pitchpoling. But if, you look at the angle of the Spray Rail, it actually would help a pitchpole once the boat drove under that far.

Also, that spray that was constantly flying off them was a lot of drag.
Today's Sharks are all Spray Rail free.
Rick