When two boats share the same hull type — in this case both the Eastern Eastern 18 2009 and the Eastern Eastern 31 2013 are modified 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 Eastern Eastern 31 2013 measures 31,3 feet overall (2013), giving it roughly 13,1 additional feet of deck space compared to the Eastern Eastern 18 2009 at 18,3 feet (2009). Weight tells a clearer story for trailering families: the Eastern Eastern 18 2009 tips the scales at 1 225 lbs — 1 213 lbs more than the Eastern Eastern 31 2013 at 12 lbs. That difference is meaningful if you're working within a half-ton or three-quarter-ton truck's tow rating, especially once you factor in a motor, gear, and fuel.
For family outings this is probably the sharpest distinction between the two. The Eastern Eastern 31 2013 is rated for 9 passengers, while the Eastern Eastern 18 2009 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Eastern Eastern 31 2013 could be the deciding factor.
Bottom line: Choose the Eastern Eastern 31 2013 if your priority is putting more people on the water — it handles 9 passengers and at 31,3 ft it has the deck room to back that rating up comfortably. The Eastern Eastern 18 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.