Jayncee,
I replaced the old Forward Shower sump pump on our 1988 45' Legend with a Seaflo Automatic Submersible Boat Bilge Water Pump 12v 750gph Auto with Float Switch that cost us $21.
It fit perfectly, didn't need a separate water float switch AND!,...it drains the waste water level in the shower sump down to 1/3rd the water level of the old arrangement. Which thrills my wife to death, because the remaining (residual) water can be mopped up with just a towel now.
Regards,
James