The Crestliner Kodiak 18 Tiller 2012 is a deep-V design and the Crestliner Sportfish Series 1850 2009 is a modified-V design, so you're likely deciding between two noticeably different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
On paper these two are close siblings in the size department - Crestliner Kodiak 18 Tiller 2012 at 18,0 ft versus Crestliner Sportfish Series 1850 2009 at 18,0 ft. Weight tells a clearer story for trailering families: the Crestliner Sportfish Series 1850 2009 tips the scales at 1 470 lbs - 660 lbs less than the Crestliner Kodiak 18 Tiller 2012 at 810 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.
The power gap is worth calling out. Rated to 175 hp, the Crestliner Sportfish Series 1850 2009 has a 105-hp advantage over the Crestliner Kodiak 18 Tiller 2012's 70-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Crestliner Sportfish Series 1850 2009 carries 33 gallons versus 17 gallons in the Crestliner Kodiak 18 Tiller 2012. 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 Crestliner Sportfish Series 1850 2009 is rated for 7 passengers, while the Crestliner Kodiak 18 Tiller 2012 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Crestliner Sportfish Series 1850 2009 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Crestliner Sportfish Series 1850 2009 comes in at 8 lbs per hp versus 12 lbs per hp for the Crestliner Kodiak 18 Tiller 2012. The lower the ratio the more explosive the acceleration - meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.
Bottom line: Choose the Crestliner Sportfish Series 1850 2009 if your priority is putting more people on the water - it handles 7 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Crestliner Kodiak 18 Tiller 2012 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.