1970 Irwin 34 vs 1977 Cal 33 — Comparison

1970 Irwin 34
VS
1977 Cal 33

Specifications Side by Side

Specification1970 Irwin 341977 Cal 33
General
ManufacturerIrwinCal
Year1970–19781977–1982
TypeSloopSloop
CountryUSAUSA
DesignerTed IrwinBill Lapworth / C. Raymond Hunt
Dimensions
LOA10.36 m (34.0 ft)10.06 m (33.0 ft)
LWL8.23 m (27.0 ft)8.08 m (26.5 ft)
Beam3.20 m (10.5 ft)3.20 m (10.5 ft)
Draft1.52 m (5.0 ft)1.60 m (5.2 ft)
Weight
Displacement5,443 kg (12,000 lbs)5,216 kg (11,499 lbs)
Ballast2,177 kg (4,799 lbs)2,177 kg (4,799 lbs)
Sailing
Sail Area47.9 m² (516 ft²)43.0 m² (463 ft²)
Hull MaterialFiberglassFiberglass
Keel TypeFullFin
Engine & Tanks
Engine18 HP18 HP
Fuel Capacity76 L (20.1 gal)68 L (18.0 gal)
Water Capacity114 L (30.1 gal)114 L (30.1 gal)
Accommodation
Berths66
Cabins22

Performance Comparison

SA/D Ratio (Higher = more sail power per displacement)
1970 Irwin 34
15.73
1977 Cal 33
14.53
Ballast Ratio (Higher = more stability)
1970 Irwin 34
40.00
1977 Cal 33
41.74
Capsize Ratio (Lower = safer offshore)
1970 Irwin 34
0.73
1977 Cal 33
0.74
Comfort Ratio (Higher = gentler motion)
1970 Irwin 34
22.58
1977 Cal 33
22.63

Detailed Comparison

The 1970 Irwin 34 and 1977 Cal 33 represent two takes on sloop-rigged sailing. The 1970 Irwin 34 is a 1970s design by Irwin from USA, while the 1977 Cal 33 is a 1970s offering from Cal from USA. The 1970 Irwin 34 was penned by Ted Irwin. The 1977 Cal 33 was designed by Bill Lapworth / C. Raymond Hunt.

In terms of size, the 1970 Irwin 34 measures 10.36m (34.0ft) overall with a beam of 3.20m, compared to the 1977 Cal 33 at 10.06m (33.0ft) with a 3.20m beam. The 1970 Irwin 34 is 0.30m longer than the 1977 Cal 33. The 1970 Irwin 34 displaces approximately 4% more than its counterpart, which significantly affects how each boat handles in different sea states.

Looking at performance, the 1970 Irwin 34 has moderate sail power suitable for relaxed cruising with an SA/D ratio of 15.73 and 47.9 m² of sail area. The 1977 Cal 33, with an SA/D of 14.53 and 43.0 m² of canvas, offers modest sail power for its displacement. The 1970 Irwin 34 has the edge in terms of raw sailing performance.

For comfort and safety, the 1970 Irwin 34 offers a moderate motion comfort level (comfort ratio: 22.6) and excellent capsize resistance suitable for offshore voyaging (capsize ratio: 0.73). The 1977 Cal 33 has a comfort ratio of 22.6 and a capsize screening value of 0.74. The ballast ratios are 40.0% for the 1970 Irwin 34 and 41.7% for the 1977 Cal 33, reflecting their respective approaches to stability.

Below deck, the 1970 Irwin 34 provides 6 berths in 2 cabins with 114L of water capacity and 76L of fuel. The 1977 Cal 33 offers 6 berths in 2 cabins with 114L water and 68L fuel capacity.

Verdict

For cruising: The 1977 Cal 33 is the better choice for comfortable cruising thanks to its higher comfort ratio, offering a gentler motion at sea that crews will appreciate on longer passages.

For racing: The 1970 Irwin 34 has the performance advantage with its superior SA/D ratio, meaning more sail power relative to its displacement for competitive sailing.

For liveaboard: Both boats provide similar accommodation, making either a viable choice for living aboard. Consider water and fuel capacity for extended stays away from marinas.

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Or view individual specs: 1970 Irwin 34 · 1977 Cal 33