What is the Southerly 105's comfort ratio?

The Southerly 105 has a Ted Brewer Comfort Ratio of 24.16. A ratio over 30 indicates good offshore comfort; over 40 is very comfortable offshore.

Is the Southerly 105 safe for offshore sailing?

The Southerly 105 has a Capsize Screening Formula value of 2.07. Values under 2.0 are considered acceptable for offshore sailing; under 1.8 is ideal.

What is the hull speed of the Southerly 105?

The theoretical hull speed of the Southerly 105 is 7.03 kn knots, calculated from its waterline length.

How much does a Southerly 105 weigh?

The Southerly 105 has a displacement of 13,001.00 lb and a length overall (LOA) of 35.43 ft.

Who designed the Southerly 105?

The Southerly 105 was designed by Dick Carter, first built in 1978.

Southerly 105 Performance — PHRF, SA/D, Hull Speed & Sailing Characteristics

The Southerly 105 is with acceptable motion comfort for coastal passages.

Hull Speed

The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.

7.0 kts

A displacement hull pushes a bow wave whose speed is limited by the waterline length. With a waterline of 27.6′, the Southerly 105 tops out around 7.0 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.

1.34 × √27.6′ LWL = 7.0 kts

Performance Ratios

Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.

Displacement / Length

277

Moderate-heavy — carries provisions well, deliberate in light air.

Comfort Ratio

24.2

Acceptable coastal comfort — fine for weekends, notice the chop offshore.

Capsize Screening

2.07

Above the 2.0 offshore threshold — best suited for coastal and protected waters.

Hull Speed

7.0kts

Pounds/Inch Immersion

1lbs

Weight needed to sink the hull one inch — loading sensitivity.

Motion & Offshore Suitability

Two ratios that matter most when you're planning passages — how the boat feels in a seaway, and whether the hull geometry is suitable for open ocean.

Comfort Ratio

24.2

Acceptable coastal comfort — fine for weekends, notice the chop offshore.

Under 20 — Snappy, racing motion

20–30 — Acceptable coastal

30–40 — Good offshore comfort

Over 40 — Very comfortable offshore

Capsize Screening Formula

2.07

Above the 2.0 offshore threshold — best suited for coastal and protected waters.

Under 2.0 — Acceptable for offshore

Over 2.0 — Coastal / protected waters

PHRF Fleet Position

Where the Southerly 105 sits on the PHRF handicap spectrum — lower numbers mean faster boats.

Racer 0–90

Cruiser/Racer 90–150

Cruiser 150–210

J/35 72s/nm

Contessa 35 114s/nm

Island Packet 35 180s/nm

How It Compares

Side-by-side with the boats most often cross-shopped against the Southerly 105.

	Southerly 105	Bristol 355	Contessa 35	Ericson 35 3	Island Packet 35	J/35
Dimensions
LOA	35.4	35.5	35.5	35.5	35.3	35.5
LWL	27.6	27.5	29.5	28.9	30.0	30.0
Beam	12.1	10.8	11.4	11.3	12.0	12.0
Displacement	13	15	13	13	17	10
Ballast	—	6	6	5	8	4
Sail Area	—	602	623	597	640	590
Performance
PHRF	—	—	114	—	180	72
SA/Disp	—	15.9	17.6	17.3	15.3	19.9
Bal/Disp	—	43.3	51.1	40.0	45.7	40.0
Comfort	24.2	32.5	26.0	25.7	31.3	27.5
Capsize	2.07	1.76	1.92	1.93	1.85	1.68
Hull Speed	7.0	7.0	7.3	7.2	7.3	8.5