It's a Yanmar 10hp - weights about 180lbs with the drive - So it wouyld be like one of me sitting back there. I think the engine hatch itself is a bigger issue - seems to take up a lot of space; in the way.
What is more interesting is beilieve this is a "Marlin" version of the Petrel - which I don't think Golden Era made many of - extended cabin, inboard, etc. Which begs the question - how is the engine configured in the original Marlin?