Agree with all, good posts.Something to consider, since we're talking pumps.I was offshore 3 years ago in a BRAND NEW 34SF Big Name with twin Yanmar turbodiesels. Beautiful boat, Rupp riggers, Pompanette chair, teak/holly cabin sole, microwave, a/c, gen., Furuno everything, all bells and whistles, 300K on the hoof. After a good shakedown on cruises in the waterway, we're yellowfin fishing 65 miles offshore in the NC gulfstream, maiden trip. Suddenly, both bilge alarms go off, 2pm in the afternoon. I'm the captain. Not my boat. Immediately go to the stern, open the long fishbox hatch, which stretches across the stern in the cockpit sole. As soon as I open the hatch, the lift-out fishbox FLOATS ONTO THE DECK.Turn off all extra pumps, close all seacocks. Water in the bilge is close to rising onto the cockpit sole. Aft pump is clogged with fiberglass matt/roving not removed from manufacture, which of course has found its way to the stern. Felt down through the seawater, cleaned off the goop from the aft pump, got her up on plane. (barely) All bilge pumps (3) ran continuously for the next 25 minutes.Got her home, dealer finally found (reiterate, finally) that the leakage was due to a failed snap connection on a water-puppy style self-priming washdown pump. Here's the kicker; this pump was mounted underneath the deck, mounted upside-down to the bottom of the deck, out of site, out of mind, but DIRECTLY above the port Yanmar. Had to stick your head way down below the hydraulic-lift engine hatch, then look hard up and to the left, to even SEE this pump. So when that snap-fitting failed, it poured salt water all over that Yanmar for several hours, finally flooding the bilge. Great engineering.Moral of the story. Know your pumps, keep them in sight, keep them quickly accessible. Run and ck. all often for leakage. And for sure, those snap-fit O ring pumps warrant extra attention. Give me an old-style pump with double stainless hose clamps any day.NEVER FORGET Murphy's Law; the boy has a nasty and dangerous way of showing himself offshore.
Aft, get the biggest that has an 1 1/8" discharge, probably a 2000. Forward, your limited to the 3/4" discharge, unless you want to re-plumb, which is not fun! I'm guessing 800-1000. Anything over that and your talking 1 1/8".