San Juan 21 Specifications

Capsize Ratio	2.45
Hull Speed	5.5
Sail Area/Displacement	23.2
Displacement To LWL	136
Length Water Line/Beam	2.429
Motion Comfort	9.55
Length overall:	20 ft 6 in
Length on waterline	17 ft 0 in
Beam	7 ft
Fractional (7/8) rig
Sail area (main and 200%)	190 sq ft (Class genoa is a 130%; in PHRF or cruising most people also have a 155%)
Spinnaker:	284 sq ft (estimate from dimensions)
Mast height:	25 ft 8 in
Draft (keel down)	4 ft 0 in
Draft (keel up)	1 ft 0 in
Displ (class minimum):	1400 lb
Keel weight:	420 lb
PHRF Rating:	252 sec/mile (w/spinnaker) 264 sec/mile (working sails)
Number built	approximately 2,700
I	22.5
P	23.00
J	8.00
E	8.75

There are three versions of the boat, all with identical hulls (the decks differ): Mark I is a regular cabin and step-down profile to the foredeck. Mark II's and III's have a flush deck all the way to the bow. II's and III's differ mostly in the length of the cabin; a Mark III cabin is about 4 inches longer than a Mark II.

For daysailer/racers SJ21's are reasonably fast though not up to the standards of J/22's or Melges 24's which are, of course, much newer and purpose-built for racing. In local club racing it can beat everything else in the club except another SJ21 and a Mirage 5.5, both of which are tough competition. Catalina 22's, Hunter 23's, the new water-ballasted Hunters, Precision 23's, etc. all are slower. The boats are well built - balsa cored deck for example - and much better built than competing boats from the 1970's and 80's such as Macgregor 21's, Mirage 5.5's, O'Day 22's etc. SJ21's have the standard 4 berths: V berth and two quarter berths.