I have a 1984 C&C 35-3. It currently has two maunal diaphram bilge pumps... First of all, will this require a new thru hull?...Thoughts and recommendations about how others have handled this??
I am in the process of installing a second automatic electric bilge pump on my boat. According to Boat/US recommendations, a boat your size should have two automatic electric pumps. As the thru-hulls will be located above the waterline and you want a fail safe system, you should have two separate thru hulls, probably best located on the transom, with anti-siphon loops at a higher point, perhaps under the cockpit seats toward the centerline of the boat, as close as you can position them to the pumps.
The corrugated hose decreases flow by as much as 30%. That may or may not matter, depending on the pump's rated flow and the diameter of the hose. My new Rulemate 750 pump will be installed with a 3/4" hose, so I doubt the hose type makes any difference.
On an attempt to clean the bilge out with a marina garden hose at nearly full volume this past summer, I was reassured by the fact that I was not able to accumulate water in the bilge as fast as my existing Rulemate 750 pumped water out. With a second Rulemate 750 working, I will have bought additional valuable minutes to locate and deal with a potential sinking situation (blown PSS shaftseal, rudder post failure, blown seacock hose, etc.) at sea.
My second pump will be connected directly to the battery bank with a Rule switch and a fuse, bypassing the battery switch and electrical panel.
In the marina, the greatest sinking danger would be due to a failure of my batteries before my next visit to the boat. My hope is my solar panel will keep the battery bank recharged sufficiently to keep my boat afloat in the event of a leak between visits.