Matching a deep vee Stanley Boats Islander I/O 21 2012 against a modified vee Stanley Boats Tiller 17 ft. - Floor 2012 means you're likely deciding between two genuinely different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
Size is the most obvious dividing line here. The Stanley Boats Islander I/O 21 2012 measures 21,7 feet overall (2012), giving it roughly 4,7 additional feet of deck space compared to the Stanley Boats Tiller 17 ft. - Floor 2012 at 17,0 feet (2012). Weight tells a clearer story for trailering families: the Stanley Boats Islander I/O 21 2012 tips the scales at 2 765 lbs — 2 757 lbs more than the Stanley Boats Tiller 17 ft. - Floor 2012 at 8 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 200 hp, the Stanley Boats Islander I/O 21 2012 has a 150-hp advantage over the Stanley Boats Tiller 17 ft. - Floor 2012's 50-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load.
For family outings this is probably the sharpest distinction between the two. The Stanley Boats Islander I/O 21 2012 is rated for 8 passengers, while the Stanley Boats Tiller 17 ft. - Floor 2012 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Stanley Boats Islander I/O 21 2012 could be the deciding factor.
Bottom line: Choose the Stanley Boats Islander I/O 21 2012 if your priority is putting more people on the water — it handles 8 passengers and at 21,7 ft it has the deck room to back that rating up comfortably. The Stanley Boats Tiller 17 ft. - Floor 2012 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.