The Regulator 31 2017 vs Regulator 34 2021 comparison sits squarely in the category of decisions where specs alone won't tell the whole story — intended use, storage, and long-term ownership costs all factor in.
Both boats share a closely matched power ceiling — 300 hp for the Regulator 31 2017 and 300 hp for the Regulator 34 2021. 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 Regulator 34 2021 carries 35 gallons versus 3 gallons in the Regulator 31 2017. 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 Regulator 34 2021 is rated for 10 passengers, while the Regulator 31 2017 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Regulator 34 2021 could be the deciding factor.
Bottom line: Choose the Regulator 34 2021 if your priority is putting more people on the water — it handles 10 passengers and at 34,0 ft it has the deck room to back that rating up comfortably. The Regulator 31 2017 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 9 that costs less to run day-to-day.