When two boats share the same hull type — in this case both the Gulf Coast Boats 220 Bay Kat (2010) 2009 and the Gulf Coast Boats GC 210 PRO 2012 are tunnel 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?
The power gap is worth calling out. Rated to 225 hp, the Gulf Coast Boats 220 Bay Kat (2010) 2009 has a 25-hp advantage over the Gulf Coast Boats GC 210 PRO 2012's 200-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Gulf Coast Boats GC 210 PRO 2012 carries 62 gallons versus 45 gallons in the Gulf Coast Boats 220 Bay Kat (2010) 2009. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
Both boats are rated for 6 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
Bottom line: Performance buyers should lean toward the Gulf Coast Boats 220 Bay Kat (2010) 2009 and its 225-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Gulf Coast Boats GC 210 PRO 2012 with its 200-hp rating is the more economical daily driver.