Didi Mini Mk3 by Dudley Dix

Radius chine plywood Mini 650

Length overall21' 4"6.5 m
Waterline length21' 2"6.45 m
Beam9' 10"3 m
Draft6' 7"2 m
Weight1907 lbs865 kg
Ballast weight705 lbs320 kg
Displacement2315 lbs1050 kg
Sail area449 sq. ft.41.70 m2
Main area338 sq. ft.31.36 m2
Jib area111 sq. ft.10.33 m2
Genoa area179 sq. ft.16.67 m2
Hull construction Plywood radius chine
See also Didi MiniDidi Cruise-Mini Mk3Didi 950

URL: http://www.dixdesign.com/didiminiMk3.htm


Low budget performer

  • Economy of plywood
  • Modern radius chine hull with topside chine
  • Stitch & glue cabintop & topside chine
  • Developed from Didi Mini concept
  • Round bilge from sheet material
  • Amateur or pro builders
  • Fixed or canting keel
  • High performance racing on a tight budget
  • Kit suppliers North America & elsewhere

In the 10 years that we have offered plans for the Didi Mini, we have sold plans for 90 boats. Apart from a redesign of the aft deck and a continual expansion of build options, it has remained the same basic boat sold as the Didi Mini Mk2. Now we introduce a major redesign, as the Didi Mini Mk3. It has some major changes from the earlier versions while retaining the same basic structure and detailing. It remains suitable for amateurs to build economically but performance will step up a notch or two.

Introduced in the Didi Mini Mk3:

  • Updated hull shape with broader stern and topside chine
  • Extended cabin roof, forming protected cuddy over front of cockpit
  • Easier access between cockpit and interior
  • More power from broader and flatter stern
  • Water ballast of fixed keel version further outboard
  • Bow and stern ballast tanks in canting keel version
  • Tacking daggerboard in canting keel version
  • Redesigned foam flotation, cleaner interior
  • Inboard chainplates for tighter genoa sheeting
  • Larger square-head mainsail
  • Carbon or aluminum spars

Overall, these changes produce a boat that will be more powerful, faster, more weatherly and more comfortable to sail.

Detailing is based on the series of radius chine plywood designs that started with my DIDI 38 "Black Cat", and was followed by the DIDI 34, Didi MG30 and DIDI 26. The underbody has been reworked to allow a topside chine to be added to power-up the aft sections. The chine is formed by stitch & glue methods and fairs into the hull side just forward of the mast, with the bow sections remaining the same as the Didi Mini.

Design principle is simplicity and to the Mini 6.5 Class limits. The design includes options of a fixed keel with conventional port & starboard water ballast tanks or a canting keel with forward daggerboard and bow and stern water ballast tanks. For the fixed keel version the tanks increase sail-carrying power. For the canting keel version the tanks allow the bow to be trimmed down on windward legs for improved windward ability or the stern to be trimmed down for offwind performance in strong winds. The daggerboard can be tacked inside the casing for increased lift. Linked twin rudders are steered by central tiller.

Keels are hollow aluminum fabrications with through-bolted beaver tail ballast bulbs. The fixed keel has optional trim tab. Both keels are supported by the hull structure by means of an internal aluminum box frame. The fixed keel has an integral post to transfer some of the keel loads through to the deck structure.

The deck layout is a fairly conventional 3-winch arrangement. The smaller headsails sheet to the top of the cabin and are led to the cabintop winch. The larger headsails and spinnakers sheet to the cockpit winches. Tweeker lines replace headsail tracks.

Spars can be either carbon for performance or aluminum for reduced cost. If an aluminum mast is used then the ballast bulb must be 10% heavier to maintain stability in the test condition.

Drawings include full size Mylar patterns of the backbone, bulbs, rudders and daggerboard. Optional full size Mylar patterns for the bulkheads are also available.

Pre-cut hull, deck and bulkhead kits will be available from various suppliers. Click here for supplier contact info. Please clarify with suppliers what is included in their prices.

We continue to sell plans for the Didi Mini alongside the Didi Mini Mk3 because there are builders who still prefer to build the older design.

Didi Mini Mk3

Deck plan
Deck plan
Interior layout
Interior layout
Hull and keel
Hull and keel

See also

Design Length Beam Sail area Engine power Compare
Didi Mini Didi Mini by Dudley Dix
Radius chine plywood Mini 650
21' 4"
6.5 m
9' 10"
3 m
437 sq. ft.
40.60 m2
Didi Cruise-Mini Mk3 Didi Cruise-Mini Mk3 by Dudley Dix
Radius chine plywood mini cruiser
21' 4"
6.5 m
9' 10"
3 m
343 sq. ft.
31.91 m2
Didi 950 by Dudley Dix
Radius chine plywood Class 950
31' 2"
9.5 m
3.65 m
864 sq. ft.
80.25 m2

Boats about same size as Didi Mini Mk3

Didi Mini   Didi Mini
Radius chine plywood Mini 650

LOA: 21' 4"/6.5 m   compare
Didi Cruise-Mini   Didi Cruise-Mini
Radius chine plywood mini cruiser

LOA: 21' 4"/6.5 m   compare
Didi Cruise-Mini Mk3   Didi Cruise-Mini Mk3
Radius chine plywood mini cruiser

LOA: 21' 4"/6.5 m   compare
  Cape Cutter 19
Plywood Lapstrake Traditional Trailer-sailer

LOA: 22' 4"/6.8 m   compare

Questions? Suggestions? Contact us at: info@boatplans.cc