Custom Mutihull Eval » IROQUOIS 30 MK II Custom Multihull Eval

Release Date: 7/8/2007

This is MDI's Comparative Trend-Line Analysis of the Iroquois 30 MK II. In the Trend-Line Analysis the MKII is compared to the MDI's Bridgedeck Clearance evaluation standards developed by Cal Markwood, along with this, the Mark II is also graphed against the Catamaran Database Trend Lines of Performance and Stability results ofall catamarans. The specific Catamaran Database Trend Lines used for thisanalysis are: Bruce Number (BN), Sail Area to Displacement ratio (SA/D), Base Speed (BSpd), Texel Rating (TR) and Stability Speed (SSpd) and Cal Markwood's Stability Index (SI-CM). This analysis comes complete with18 specifications,10 are unique performance and stability evaluations, profile and layout drawing are also included.

"As much a true racer as a cruiser, the Iroquois 30 MK II is fast, weatherly, seakindly and tracks assuredly. She has a feather-light helm, a useful sail plan and a tabernacle mast that makes her easy to handle both in and out of the water. Windward ability is excellent, aided by kick-up rudders and pivoting centerboards. One of the handiest and most affordable catamarans in this size range, the Iroquois can still hold her own among the newer designs." Sailor's Multihull Guide, 1st Ed., 1994.


MDI Comparative Multihull Analysis


By Rod McAlpine-Downey


Basic Specifications:

Bcl 10.18 ft., 3.10 m

Bh 3.32 ft., 1.01 m

BdCl: 15 in 38.10cm


3.03 LT

6787.20 lbs

3078.62 kg

SA 345 sq.ft., 32.05 m2 (main and foretriangle, Jib area only)

Bcl/Lwl .38

Lwl/Bh 8.06

BdCl v. Nom: -5in -13cm

Performance Indicators:

SA/D 15.40

BN .98

BSpd 7.38

PI-C .58

Texel 157

Stability Indicators:

SI-CM 3.40

SSpd 21.17 kts

Reprinted by permission of

Kevin Jeffrey from Sailor's

Multihull Guide, 1st Ed.

Copies of all 3 editions are

for sale in the MDI Bookstore,

as well as other books

by Kevin and Nan Jeffrey.


MDI reports comparison data with other vessels selected by Cal Markwood. The comparisons are offered in two ways. In Cal's Evals Mr. Markwood gives related LWL vessel AVERAGES. On the graphs below we use TREND LINES of the entire Type Database, i.e. Catarmaran or Trimaran as appropriate.

While the Trend lines are accurate, the sailboat location on the graphs may not be exact. The graphs are intended as a quick reference for the reader to establish at a glance where the above vessel is located on the "Type Trend" line. Actual data used in locating the vessel on each Trend line is listed above. It may be used by the reader to evaluate the precise and exact location of this vessel on the graph.

Below you will find the 6 graphs with Type Trend Lines. These Trend Lines are not averages or means, but rather are statistical evaluations that give the "apparent relationship" of the Iroquois 30 MK II with the 658 Catamarans in the Database. The sailboats on the graphs represent the MK II. For a more indepth understanding of these graphs and their results please read the Technical pages


BeautifulIroquois MK II