When two boats share the same hull type — in this case both the Champion Boats 186 Coastal 2008 and the Champion Boats 20 Sea 2008 are modified vee designs with composite 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 Champion Boats 186 Coastal 2008 measures 18,0 feet overall (2008), giving it roughly 16,0 additional feet of deck space compared to the Champion Boats 20 Sea 2008 at 2,0 feet (2008). At 19 lbs and 2 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.
Both boats share a closely matched power ceiling — 200 hp for the Champion Boats 186 Coastal 2008 and 200 hp for the Champion Boats 20 Sea 2008. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup. Fuel capacity breaks the other way: the Champion Boats 20 Sea 2008 carries 52 gallons versus 32 gallons in the Champion Boats 186 Coastal 2008. 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 Champion Boats 186 Coastal 2008 is rated for 6 passengers, while the Champion Boats 20 Sea 2008 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Champion Boats 186 Coastal 2008 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Champion Boats 20 Sea 2008 comes in at 0 lbs per hp versus 0 lbs per hp for the Champion Boats 186 Coastal 2008. 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 Champion Boats 186 Coastal 2008 if your priority is putting more people on the water — it handles 6 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Champion Boats 20 Sea 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.