I am looking to move down in size from my 1996 Mainship 34MY. It is a great boat for the dock but not very economical to cruise the Great Lakes and as we are preparing for retirement “economical” plays a big role. I know it will be a big adjustment from a livability standpoint but we are ready for the change. With that being said I really like the size of the Sea Ray 310 Sundancers and that is what we want once we sell the current boat. In looking at the 310 I have a couple of questions...I came across one with 5.7 Horizon Bluewater engines and I am not familiar with these can someone please educate me? Also, I know these boats come in shaft or stern drive and the shaft is rare to find. I am not familiar with the stern drives so could someone educate me please on why I would want stern over shaft?