When two boats share the same hull type — in this case both the Tidewater Boats 1784 2010 and the Tidewater Boats 2196 2010 are tri-hull 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?
The power gap is worth calling out. Rated to 150 hp, the Tidewater Boats 2196 2010 has a 60-hp advantage over the Tidewater Boats 1784 2010's 90-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Tidewater Boats 1784 2010 carries 19 gallons versus 3 gallons in the Tidewater Boats 2196 2010. 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 Tidewater Boats 2196 2010 is rated for 6 passengers, while the Tidewater Boats 1784 2010 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Tidewater Boats 2196 2010 could be the deciding factor.
Bottom line: Choose the Tidewater Boats 2196 2010 if your priority is putting more people on the water — it handles 6 passengers and at 21,0 ft it has the deck room to back that rating up comfortably. The Tidewater Boats 1784 2010 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.