When two boats share the same hull type — in this case both the Navigator Yachts Navigator 5100 2009 and the Navigator Yachts Navigator 6800 2013 are deep vee designs with fiberglass construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?

Size is the most obvious dividing line here. The Navigator Yachts Navigator 5100 2009 measures 51,7 feet overall (2009), giving it roughly 44,7 additional feet of deck space compared to the Navigator Yachts Navigator 6800 2013 at 7,0 feet (2013). At 5 lbs and 9 lbs respectively, both sit in a similar weight class — either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.

The power gap is worth calling out. Rated to 900 hp, the Navigator Yachts Navigator 6800 2013 has a 400-hp advantage over the Navigator Yachts Navigator 5100 2009's 500-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Navigator Yachts Navigator 6800 2013 carries 14 gallons versus 6 gallons in the Navigator Yachts Navigator 5100 2009. 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 Navigator Yachts Navigator 6800 2013 is rated for 21 passengers, while the Navigator Yachts Navigator 5100 2009 caps at 15. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Navigator Yachts Navigator 6800 2013 could be the deciding factor.