The Sonar is aggressively canvassed for its weight, with a quick, snappy motion best suited to day sailing.
Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 19.9′, the Sonar tops out around 6.0 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √19.9′ LWL = 6.0 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
SA / Displacement
25.9
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
44.3%
Stiff enough to carry a big genoa comfortably into moderate breeze.
Displacement / Length
119
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
10.0
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.45
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
557lbs
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
10.0
Quick, snappy motion — better for day sails and racing than long passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
2.45
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 Sonar sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Kirby 23
180s/nm
San Juan 23
236s/nm
Pearson 23
240s/nm
Estimated Speed by Wind
Rough boat speed estimates at different true wind speeds and points of sail — derived from hull speed, SA/D, and displacement, not measured polars.
| Point of Sail |
6 kts TWS |
10 kts TWS |
15 kts TWS |
20 kts TWS |
| Close-hauled40–50° |
2.8 |
3.6 |
4.0 |
4.1 |
| Close Reach60° |
3.4 |
4.3 |
4.8 |
5.0 |
| Beam Reach90° |
4.2 |
5.3 |
5.9 |
6.4 |
| Broad Reach120–135° |
3.9 |
4.9 |
5.5 |
5.9 |
| Run150–180° |
3.1 |
3.9 |
4.4 |
4.5 |
These are simplified estimates based on hull speed (6.0 kts),
SA/D (25.9), and empirical efficiency curves — not instrument-measured
polars. Real-world speed varies with sea state, bottom condition, sail trim, and current.
Speeds in gold approach hull speed;
bold gold means near or at hull speed.
Wind Range & Comfort Envelope
Estimated wind ranges for comfortable sailing on the Sonar — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–5 kts
5–18 kts
18–28 kts
28+ kts
Ghosting
0–5 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
5–18 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
18–28 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
28+ kts
Storm conditions. Storm jib or bare poles. Seek shelter if coastal.
How It Compares
Side-by-side with the boats most often cross-shopped against the Sonar.
|
Sonar |
Blazer 23 Kirby |
Ericson 23 2 |
Kirby 23 |
Pearson 23 |
San Juan 23 |
| Dimensions |
| LOA |
23.0 |
23.0 |
22.9 |
23.0 |
23.0 |
23.0 |
| LWL |
19.9 |
18.8 |
19.5 |
18.8 |
20.0 |
20.3 |
| Beam |
7.8 |
7.9 |
7.9 |
7.8 |
8.0 |
8.0 |
| Displacement |
2 |
2 |
3 |
2 |
3 |
2 |
| Ballast |
930 |
900 |
1 |
900 |
1 |
960 |
| Sail Area |
265 |
— |
— |
271 |
238 |
— |
| Performance |
| PHRF |
— |
— |
— |
180 |
240 |
236 |
| SA/Disp |
25.9 |
— |
— |
24.3 |
16.6 |
— |
| Bal/Disp |
44.3 |
40.9 |
38.7 |
— |
37.1 |
35.6 |
| Comfort |
10.0 |
— |
— |
12.1 |
16.3 |
— |
| Capsize |
2.45 |
— |
— |
2.32 |
2.11 |
— |
| Hull Speed |
6.0 |
— |
— |
5.8 |
6.0 |
— |