I've used the Oil Boy fluid extractor for years on my last boat and similarly to jef, I highly recommend it. Prior to that with previous boats, I had another brand ( called the Bilge Buddy - or something to that effect ) that really sucked big time (not).
My current boat has an integrated piston pump oil changer, OE as installed by Nauticat in Finland and permanently mounted on an engine room bulkhead. Don't know what it's called or where it was made - but it works great. The pump consists of an all brass cylindrical body, spout and plunger, connected to the oil pan by heavy rubber hose.
It really makes the job of changing engine oil quick and clean - I simply place a jug under the spout and pump a few times.
True Blue . . .
sold the Nauticat