I made up a funnel with a hose that runs out the bilge plug at the back to an oil catch pan, I then drop the nose of the boat so the sump plug is down, pop the plug out and let gravity do the rest! Tests show you need more than a garden hose to get the old oil out of the funnel faster than it fills and overflows but heck, I needed an excuse to clean the bilge again anyway!
I also put a small bucket under the remote filter mount when I drop the filter too. Just to catch the oil from there. I take a line off the cooler and blow the old oil out of that too. It tastes terrible but it gets it out!

(Actually I add that to the drain funnel...)
I'm not sure if it's a good idea or not, but I pre-fill the cooler before the engine and always let some clean oil run through the engine from the fill straight out the sump hole (about 1/2 quart) before I plug it back up to fill.
Hope that helps!
John