Cal's Evals » KENNEX 380

Release Date: 1/1/2011

Kennex 380

The Kennex 380 is an early 1990s cruising catamaran with vertical stems and sloped-off sterns reflecting very contemporary styling. The Multihull Dynamics, Inc. (MDI) evaluation of the boat in comparison with 37 other cruising catamarans with comparable waterline lengths is as follows:

Displacement: 5.50 tons [6.05 tons average (range 2.47 to 14.25 tons)]

Length Overall: 37.9 feet [39.6 feet (range is 37.75 to 46 feet)]

Length at Waterline: 37.9 feet [38 feet (range is 37.4 to 38.53)]

Sail Area (Main plus 100% fore-triangle): 969 sq. ft. [934 sq. ft. (range is 634 to 1227)]

Sail Area/Displacement Ratio: 29.06 [27.55 (range is 19.51 to 40.34)]

Beam between hull centerlines: 15.93 ft. [18.09 ft. (range is 15.7 to 23.29)]

Bridgedeck Clearance (Unknown) [29 in. is nominal for 38 ft. LWL catamarans

]

Hull Waterline Length/ Beam ratio: 10.1 [10.2 (range is 7.17 to 15.03)]

Base Speed: 10.86 knots [10.63 (range is 9.26 to 12.46)]

Texel Rating: 117 [121(range is 99 to 143)]

Bruce Number: 1.35 [1.31(range is 1.11 to 164)]

Stability Speed: 16.1 knots [18.38 (range is 12.43 to 22.72)]

The other boats used for comparison are the KSS 42 2ma, Manta 38, Leopard 40, IRC 1200, Maxim 380, Punch 11.5, Boatcraft 12.0, Moorings 4200, Leopard 42, VIK 115, Cosmo 1160, Waterline 1160, Hughes 38, Catflotteur 41, Catina, Helios 38, Athena 38, Outremer 38, Catana 38, Mystery Cove 380, Fastcat 395, Archipelago 400, Tiki 46, Grainger 40, Catana 381, Privilege 42, Norseman 400, Lidgard 39, Maxim 380 MkII, TC 12.2, Farrier 40, Lagoon 410, Island Spirit 40, Dazcat 11.8M and Line Honors 1220.

The Kennex 380 is lighter than average and has a slightly larger than average sail area, resulting in about two tenths knot faster base speed. The smaller than average beam between hull centerlines accounts for the lower than average Stability Speed. Cruising catamaran designs in the two decades since the Kennex 380 was designed generally have a Bcl/Lwl (beam between hull centerlines to waterline length) ratio of .5 or 50%. Bcl/Lwl is just 42% for this boat, so it is less stable (Stability Speed) and sail shortening will need to occur a lower wind speed.

With the Lwl/Bh (hull waterline length to beam) ratio of 10.1, it is in the cruising/racing category by Charles Kanters method of categorizing multihulls. The boat has spade rudders and low aspect ratio keels, the latter showing a bias toward the cruising category.

Calvin H. Markwood
Engineering Analyst
Multihull Dynamics, Inc.

Contact Cal: multihull.analysis@comcast.net

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