The Jeanneau Merry Fisher 645 2014 vs Jeanneau Yachts 51 2016 comparison sits squarely in the category of decisions where specs alone won't tell the whole story — intended use, storage, and long-term ownership costs all factor in.
The power gap is worth calling out. Rated to 110 hp, the Jeanneau Yachts 51 2016 has a 60-hp advantage over the Jeanneau Merry Fisher 645 2014's 50-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Jeanneau Merry Fisher 645 2014 carries 136 gallons versus 63 gallons in the Jeanneau Yachts 51 2016. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
For family outings this is probably the sharpest distinction between the two. The Jeanneau Yachts 51 2016 is rated for 15 passengers, while the Jeanneau Merry Fisher 645 2014 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Jeanneau Yachts 51 2016 could be the deciding factor.
The Jeanneau Yachts 51 2016 has a documented displacement of 31 747 lbs. Displacement data wasn't available for the other boat in this comparison.
Draft is a practical consideration that many buyers underestimate until they're already at the marina. The Jeanneau Yachts 51 2016 draws 7,6 ft, compared to 1,8 ft for the Jeanneau Merry Fisher 645 2014. That 5,8-foot difference affects which anchorages you can access, which haul-out facilities will take you, and how carefully you need to read the tide tables in shallower cruising grounds.
For auxiliary power the Jeanneau Yachts 51 2016 carries a 110-hp engine against 50 hp on the Jeanneau Merry Fisher 645 2014. Motoring range and ability to punch through a foul current or enter a tight marina under power will favour the more powerful installation.
Bottom line: The Jeanneau Yachts 51 2016 at 50,6 ft offers more living space, greater range, and a more substantial offshore capability. The Jeanneau Merry Fisher 645 2014 at 22,0 ft is the easier, lower-cost option — simpler to crew and a strong choice for coastal and day sailing.