The Imx 45 is aggressively canvassed for its weight.
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 39.3′, the Imx 45 tops out around 8.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √39.3′ LWL = 8.4 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
30.1
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
45.4%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
148
Ultralight — responsive and fast, but carries less stores.
Capsize Screening
2.01
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
SA/Disp (Calculated)
24.2
Computed from measured I/J/P/E rather than reported sail area.
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.
Capsize Screening Formula
2.01
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 Imx 45 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Hunter 45 Legend
83s/nm
Tartan 4400
96s/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° |
4.0 |
5.0 |
5.6 |
5.8 |
| Close Reach60° |
4.8 |
6.0 |
6.8 |
7.0 |
| Beam Reach90° |
5.9 |
7.4 |
8.3 |
9.0 |
| Broad Reach120–135° |
5.4 |
6.9 |
7.7 |
8.3 |
| Run150–180° |
4.3 |
5.5 |
6.1 |
6.4 |
These are simplified estimates based on hull speed (8.4 kts),
SA/D (30.1), 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 Imx 45 — 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 Imx 45.
|
Imx 45 |
Contest 42Cs |
Hunter 45 Legend |
Outremer 45 |
Sun Odyssey 44I Perf Jeanneau |
Tartan 4400 |
| Dimensions |
| LOA |
— |
45.0 |
45.0 |
45.0 |
45.1 |
45.0 |
| LWL |
39.3 |
38.2 |
38.6 |
44.6 |
37.6 |
37.5 |
| Beam |
13.6 |
13.5 |
14.3 |
23.6 |
14.3 |
14.1 |
| Displacement |
20 |
29 |
23 |
15 |
21 |
24 |
| Ballast |
9 |
11 |
9 |
— |
6 |
9 |
| Sail Area |
1 |
1 |
900 |
1 |
1 |
— |
| Performance |
| PHRF |
— |
— |
83 |
— |
— |
96 |
| SA/Disp |
30.1 |
18.2 |
17.8 |
— |
23.0 |
— |
| Bal/Disp |
45.4 |
37.8 |
40.0 |
— |
28.9 |
37.5 |
| Comfort |
— |
35.9 |
25.3 |
8.1 |
24.5 |
— |
| Capsize |
2.01 |
1.74 |
2.01 |
3.76 |
2.05 |
— |
| Hull Speed |
8.4 |
8.3 |
8.3 |
9.0 |
8.2 |
— |