The Jpk 1050 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 26.6′, the Jpk 1050 tops out around 6.9 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √26.6′ LWL = 6.9 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
32.3
Performance-oriented — carries a lot of canvas for its weight.
Comfort Ratio
14.9
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.35
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
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
14.9
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
2.35
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 Jpk 1050 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
J/39
45s/nm
Swan 391
90s/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° |
3.3 |
4.1 |
4.6 |
4.8 |
| Close Reach60° |
3.9 |
5.0 |
5.6 |
5.8 |
| Beam Reach90° |
4.8 |
6.1 |
6.8 |
6.9 |
| Broad Reach120–135° |
4.5 |
5.6 |
6.3 |
6.6 |
| Run150–180° |
3.6 |
4.5 |
5.0 |
5.3 |
These are simplified estimates based on hull speed (6.9 kts),
SA/D (32.3), 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 Jpk 1050 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–5 kts
5–16 kts
16–24 kts
24+ kts
Ghosting
0–5 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
5–16 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
16–24 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
24+ 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 Jpk 1050.
|
Jpk 1050 |
Akilaria 40 |
Catalina 386 |
J/39 |
Swan 391 |
X 1 Ton |
| Dimensions |
| LOA |
39.9 |
40.0 |
39.8 |
39.8 |
39.9 |
39.8 |
| LWL |
26.6 |
40.0 |
34.4 |
33.5 |
33.1 |
33.1 |
| Beam |
11.6 |
14.7 |
13.1 |
13.0 |
12.4 |
12.9 |
| Displacement |
7 |
10 |
17 |
16 |
18 |
13 |
| Ballast |
3 |
3 |
5 |
6 |
6 |
— |
| Sail Area |
785 |
1 |
807 |
720 |
767 |
818 |
| Performance |
| PHRF |
— |
— |
— |
45 |
90 |
— |
| SA/Disp |
32.3 |
42.1 |
19.0 |
16.9 |
17.4 |
23.5 |
| Bal/Disp |
— |
36.6 |
29.2 |
39.4 |
— |
— |
| Comfort |
14.9 |
11.0 |
24.9 |
33.7 |
29.0 |
19.2 |
| Capsize |
2.35 |
2.72 |
2.01 |
1.61 |
1.87 |
2.19 |
| Hull Speed |
6.9 |
8.5 |
7.9 |
9.4 |
7.7 |
7.7 |