My 1984 S2 8.6 has a sump-pump that is activated by power panel switch, but does NOT have a float switch in the bilge. I believe the pump is the original. My question is, "Is there something I should know that precludes adding a float switch?" I would have thought that the original owners would have added this item.
Many boats that were concieved more as racing hulls than cruisers don't have enough of a bilge sump to accomodate a typical float switch. I've seen such switches installed, but they would only work if the floors were up. I suppose they'd work eventually once the floors floated off.
We had a similar problem in our last boat, limited clearance for a float switch.
There are conductivity based switches now that look attractive, with the added bonus that, since diesel & gas are non conductive, would stop pumping if fuel got into your bilge.