The Southerly 420 2020 vs Southerly 435 2017 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.
On paper these two are close siblings in the size department — Southerly 420 2020 at 42,7 ft versus Southerly 435 2017 at 42,2 ft. Weight tells a clearer story for trailering families: the Southerly 435 2017 tips the scales at 26 015 lbs — 1 012 lbs less than the Southerly 420 2020 at 25 003 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.
Both boats share a closely matched power ceiling — 57 hp for the Southerly 420 2020 and 53 hp for the Southerly 435 2017. 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 Southerly 420 2020 carries 82 gallons versus 76 gallons in the Southerly 435 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 Southerly 420 2020 is rated for 13 passengers, while the Southerly 435 2017 caps at 12. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Southerly 420 2020 could be the deciding factor.
Both boats sit in a similar displacement bracket — 25 003 lbs for the Southerly 420 2020 and 26 015 lbs for the Southerly 435 2017. Comparable displacement means broadly similar seakeeping behaviour and load capacity, though hull form and ballast ratio will still produce noticeably different sailing characteristics.
Both boats draw a similar depth — 8,1 ft and 8,1 ft respectively. Marina access and anchorage options should be broadly equivalent between the two.
The Southerly 420 2020 is rigged as a fractional_rig_sloop while the Southerly 435 2017 carries Sloop rigging — a meaningful difference in sail handling complexity, upwind performance, and the size of crew you'll need to work the boat comfortably. Helm style differs too: the Southerly 420 2020 uses a 2 wheels versus a 1 wheel on the Southerly 435 2017. Wheel helms give better leverage and visibility on larger boats; tillers offer direct feedback and simplicity on smaller ones.
Hull speed is rated at 8,1 knots for the Southerly 435 2017 and 8,1 knots for the Southerly 420 2020.
Bottom line: The Southerly 420 2020 and Southerly 435 2017 are closely matched on paper. A sea trial on both in representative conditions is the only reliable way to find which one suits your sailing style, home port, and intended cruising ground.