Time Tested A Guide To Good Old Boats Reprinted by permission of Chesapeake Bay magazineby Tom Dove
Rainbow 24 Drawn by a renowned designer nearly 40 years ago, this tough, humble little daysailer remains a great way to get into boating. “GIVE ME A BOAT THAT WILL BRING BACK SIX DRUNKS WHO WERE CAUGHT IN A THUNDERSTORM," Jerry Wood told legendary designer Olin Stephens in 1961. Wood, the founder of Annapolis Boat Rentals and Annapolis Sailing School needed a vessel simple enough for novice sailors and tough enough for renters.
The 24-foot Rainbow was the result, and about 500 of the Sparkman & Stephens vessels were produced by Tidewater Boats in Maryland before the factory closed in 1977 It's still a popular class, and you can find one of these daysailers riding quietly on a mooring or sliding gracefully across the water almost anywhere along the coast, on inland waters of upstate New York or around the Great Lakes. They still are raced here on the Chesapeake.
The same attributes that make it an ideal rental and learning boat--responsiveness, comfortable seating, low maintenance, stability and ruggedness--make it a perfect family daysailer. I owned a Rainbow (we named it Legato for its smoothness) and taught sailing aboard others on the Chesapeake and in the Florida Keys, and I have great respect for these little vessels. My wile and I loved on the Severn River then, and we often took our two children out for daysailing, picnic trips, racing and even overnighting. It was pretty snug for sleeping aboard (two in the cuddy cabin and two on the cockpit seats), but we had fun. We bought the boat for a reasonable price and sold it for the same amount; I visited her on Lake George, N.Y., a few years ago, just to pat her transom and say, hello.
A Rainbow 24 Cuddy Cabin model scoots off the wind; Olin Stephens grabs a photo
Test Sail
Stability and safe sailing are the Rainbow's strong points. The mast is short by today's standards and the ballast is concentrated in a bulb at the bottom of the keel, so the heeling moment is not as great as in a boat with a tall mast and
shoal draft. This boat likes to sail upright, and if you drive it hard enough to put the rail under, you're losing speed. That's a happy coincidence with the wishes of most new sailors--and their families.
Carry too much sail in a strong wind and the rudder will come out of the water at extreme angles of heel. A Rainbow then rounds up into the wind and gives you time to think about what you have just done. There's no way to capsize this boat under working sails, as weather helm provides a safety valve to overpowering. By the way, that distinctive horizontal plate on the rudder is there to prevent ventilation of the rudder at high angles of heel and consequent loss of control.
With my wife and two guests aboard. I took a knockdown under spinnaker in 25 knots of wind (yes, that was a stupid thing to do, but it was fun until the puff hit). Thinking the chute was history. I said. "That's it. We've had it." The crew looked at each other and paled, thinking I meant we were going to capsize or sink. There are certain phrases a skipper should never use, and this, I learned, was one. The boat popped right back up once the sheet was eased, and we gathered the spinnaker and sailed on home.
Light air is the Rainbow's weakness there's a good sail-area-to-displacement ratio, but the low-aspect sail is not as efficient as a tall rig and the wetted surface is greater that in most modem boats. With a genoa and a spinnaker, it will move along all fight, but a J-24 will sprint right by it.
A properly tuned Rainbow tacks in about 80 to 90 degrees and claws out to windward nicely with little leeway; the genoa enormously improves windward performance over the working jib. All around, this boat is faster than most of its contemporaries, such as the Pearson Ensign.
On Deck
The cockpit is the most comfortable of any boat I've sailed. The seat backs are high for excellent support, the footwell is deep and the width of the cockpit is perfect for bracing against heeling and waves. One sails in this boat, not on it. While six can daysail it, this vessel is much more comfortable for four, and the rig is easy for a singlehander or a couple. Racing with a spinnaker calls for a crew of three or four. 
The tradeoff for this comfort in a 24-footer is that the cockpit is too deep to be self-draining. Rainbow owners either rig a tarp over the boom as a tent to keep the rain out or bail out the bilge after each storm.
The side decks are narrow--about the width of an average shoe. The afterdeck has a big lazarette with space to store an outboard, fuel tank, fenders and other necessities. Halyards go to cleats on the mast, and the original reefing system was a rolling boom. Nearly all owners have switched to conventional slab reefing or "Jiffy" systems, a change that should cost no more than $200.
Cabin
The cabin is a small cuddy with a V-berth that is okay for an average-sized couple. Many boats originally had flush-through marine toilets, but most owners have either removed them or substituted portable, self-contained units. A few Rainbows had a tiny single-burner Sterno "Sea Swing" stove mounted inside. With the stove, a cooler for food, ventilation from opening ports (an option) and the cabin hatch, camp cruising was--and still can be---pretty pleasant.
Design
The hull lines are classic and, from some angles, quite beautiful. There's moderate overhang at the bow and stern, and the transom is nicely proportioned. The low cuddy cabin does not detract from the lines of the basic Rainbow, although there are three distinctive variants that make the boat less sleek.
About 25 boats were built with a deck mold that had a sort of double bubble on top, which increased the cabin space significantly. While still a very small cruiser, this Weekender model had four bunks, a sink and stove and sitting headroom. The cockpit is somewhat smaller on these boats, and they do not have the foam flotation that's installed under the seats of the standard Rainbow.
The U.S. Naval Academy has a fleet of Knockabouts, which are Rainbows with completely open cockpits--and no cuddy cabin--that wilt accommodate eight midshipmen. A few of these are also used by the Annapolis Sailing School. 
Finally, a radically different deck mold was designed by Peter Van Dine in the 1970s to create the Annapolis 25, which has a fairly livable cabin for a couple with two children. You won't recognize this as the Rainbow, but it really is.
A trailer is useful, but custom-fitted ones for the boat are nearly impossible to find now. New trailers have adjustable pads that can be configured to fit a Rainbow. Most owners keep their boats in the water, as a crane is necessary for launching from the trailer.
A typical engine is a 4- to 6-bp longshaft outboard that's either mounted on the transom or on a bracket attached to the transom.
Construction
This is a plain vanilla boat. The only exterior wood is the cabin door, and everything is built for easy maintenance and repair. According to Annapolis Sailing School's Operations Manager, Tim Dowling, there are only two common problems. (Since the school refurbishes its boats every two years, he has seen everything that can happen to a Rainbow.) The top bearing of the rudderpost was troublesome in all of the boats. The cure is a bronze flange by Buck Algonquin Marine Hardware (available at Fawcett Boat Supply in Annapolis, 410-267-8681). The tiller head was also a weak spot. A replacement by Spartan is also available at Fawcett. "Somebody with reasonable mechanical ability can fix either one," Dowling says.
The mast compression post in the cabin is galvanized iron, and if it has been standing in water for a long time, will rust away. If the turnbuckles are fully tightened and the rigging is still slack, it's time to replace the support post, as the mast has been driven downward into the cabin top. This is a simple and inexpensive repair--you can use galvanized plumbing pipe for the new post, just like the old one. It's worthwhile to install a proper masthead-mourned topping lift to replace the little snap that is swaged to the backstay in the original rig. All the rigging and spars are available (though the Knockabout does not use the same mast section) through Dwver Aluminum Mast Company), in
North Branford. Conn. (203--484-0419 or www.dwyermast.com). If you need to replace the genoa track (and you may, as the cars for it are not available any more), you'll have to cut access holes from the cuddy to reach some of the bolts. Chainplate problems are very rare, which speaks well for the construction quality, but bow fittings sometimes get smashed in rough use. Kato Marine in Annapolis (410-269-1218) is the best source for stemhead fittings and chainplates because they have the patterns for both. Order them unpolished to save a substantial amount of labor cost.
The ballast is cast iron and generally trouble-free, as most were encased in fiberglass; the first boats had 900 pounds of ballast, which was soon upped to 1,100 pounds for better stability. Dowling reports no problems with the Styrofoam flotation in any of the boats.
A few very early Rainbows had a fatal flaw. The first hull-to-deck joint was "U" shaped in cross section and, if broken by impact, is impossible to repair. "There's nothing else you can't fix." says Dowling. "It takes a lot of chainsaw blades plus running over the things with a forklift to break up a hull for disposal."
The sailing school sprays their boats with Awlgrip, but a private owner would spend twice as much for that as to buy the boat. Rolling on a two-part linear polyurethane paint will spiff up the finish pretty nicely.
Blistering? The Coast Guard called Jerry Wood during the Great Boat Pox Epidemic of the 1980s to ask why Rainbows never blistered, even when stored afloat for years. He didn't know why either, but they don't.
Conclusions
I will argue that Rainbows were the major force in making Annapolis a sailing town. In the 1950s, the little city was a somnolent backwater with a few motorboats and sailing dinghies, but the presence of rental and sailing school boats at the mouth of the Severn every weekend set a public perception that it was a place to sail. And so it has become.
You can own a bit of this history and have a lot of fun with it. Annapolis Sailing School remains a good source of information on Rainbows and their local fleets: (410) 267-7205: e-mail annapway@clark.net. About $1.000 to $1,200 will buy a "turnkey" Rainbow that will be ready to enjoy, while overall prices seem to range from $900 to $2,500 for boats in 'varying stages of dress or distress. Look in the classified ads and on bulletin boards, or just inquire if you see what appears to be an unused boat languishing in a harbor. They're plentiful, inexpensive, strong and comfortable. What more could a new sailor want?
BuilderTidewater Boats Annapolis, Md. (no longer in business) DesignerSparkman & Stephens Production1962-1977 LOA24'2'LWL 17'3' Beam6'3'Draft 3'6' Displacement2,200 lbBallast 1,100 lb Sail area.214 Sq. Ft. Power 4- to 6- hp, long shaft outboard Displacement/Length 182.6 (moderately light); Sail Area/Displacement 20.9 (moderately high, based on actual area); Ballast/Displacement 0.50 (high); Limiting Hull Speed 5.6 knots; Capsize Screening Value 1.95 (U.S Sailing considers a value below 2 desirable for offshore operation). Comfort Value 14.6 (Low)
CHESAPEAKE BAY MAGAZINE July 1999 27
RAINBOW CLASS·BY HUGH WHALL
Class Name and Address: Rainbow Class Association; Edward P. Covert, 4 Whiteoak Court, West Severna Park, Maryland, secretary. Class Dues: $5 per boat, $5 initiation fee, and $3 for associate members. Sail Insignia: Red, yellow, and blue rainbow.
SPECIFICATIONS:
Length over-all, 24 feet 21/2 inches. Waterline length, 17 feet 3 inches. Beam, 6 feet 3 inches. Draft, 3 feet 6 Inches. Displacement, 1,750 pounds. Keel weight, 810 pounds, plus or minus 15 pounds. Sail area, 218 square feet. Construction, fiberglass. Price, $2,695 Builder: Tidewater Boats, Inc., Box 1571, Annapolis, Maryland.
When the name Sparkman & Stephens is mentioned, most sailing people have a mental picture of big ocean, racers s.ch as Dorade, Bolero, the New York Thirty. Twos, the Twelve Meter Columbia, the Six Meter Goose, or any of the hundred and one other vessels of like character designed by this firm. However, Sparkman & Stephens is also responsible for the design of many small class boats as well. For instance, the firm designed the Lightning and its smaller sister the Blue Jay. They also have planned many small cruising-racing boats such as the Tartan and New Horizons, the latter a comfortable boat that to us lacks the flair of many of the designs from this illustrious firm.
Another boat recently designed by Sparkman & Stephens is the Rainbow, a fin-keeled, fiberglass sloop that is currently growing into a national class.
The Rainbow reflects the current tendency to leap into production before the boat is thoroughly tested. The original Rainbow, for instance, is quite different from the latest model. The prototype that quite a hit of trouble with her rudder. Like many fin keel boats she was liable to spin out when site heeled over too far and her rudder lost its bite on the water. On a reach, with a spinnaker set and lugging her over until the lee rail was awash, her rudder would be slicing along in water disturbed by the passage of the fin keel. Before you could say "let go the sheet" she would round up into the wind with the spinnaker blowing back into the cockpit. After a great deal of trial and error this problem was overcome by attaching cavitation plates to the rudder blade similar to those used on outboard engines.
Another snag was the Rainbow's tenderness. In the light, or comparatively light, airs of Chesapeake Bay the sloop behaved satisfactorily; but when sailed in regions where the wind was inclined to snort a bit, it was found she needed more ballast than the standard 810 pounds of lead. To overcome this shortcoming, cheek pieces of iron weighing a total of 150 pounds were made available by the builder to be bolted onto the bulbs of standard boats. However, it has been stipulated in the rules that only heals having similar ballast can race against each other. During the Rainbow Class Nationals any boat having the additional ballast must remove it before competing.
There were numerous other minor alterations such as, fitting ports into the cuddy, changing the bow plate, stem head tilting, and fiddling with actual construction techniques. The point is, the Rainbow, like so many other so-called stock boats which go through at, evolutionary stage after' the first few boats are built, took a year to settle down into final shape. This somewhat dilutes the one-design concept.
Be that as it may, the present rainbow is a fine little' boat. She has a deep cockpit with coamings that form good backrests while sailing off the wind but which somewhat dent the crews thighs while I hiking on the wind. Her little cuddy cabin can form somewhat cramped overnight accommodations, and some are fitted with heads. She has a rather straight sheer, a cut-off counter stern, a bow that perhaps is her only identifying Sparkman & Stephens' mark, and, as mentioned above, a fin keel with iron bulb. Her construction is typical of many fiberglass boats of her type and her spars are aluminum. A full suit of sails consists of main, jib, genoa, and spinnaker.
As far as handling goes, tile present Rainbow handles well. In a twelve to fourteen-mile breeze, the crew must stay up, on the weather rail--this is usual racing practice, of course. At least one member should be kept well forward, either in the cuddy or on the deck ahead of the shrouds. In a hard breeze the crew have their hands full sailing a Rainbow not fitted with the additional ballast and this goes double if a spinnaker is used on a reach. Off the wind she handles easily in light to moderate air and, furthermore, she will do all that is asked of her under main alone. But fin keel or no, crew weight is vital and must be properly utilized if the Rainbow is to do her best racing. While day sailing, though, the crew can relax in the big, deep cockpit--but they should sit on the weather seat, if possible.
There are fleets of Rainbows from the East to the West Coasts and down as far as Florida, with the number of boats increasing rapidly. A class association has been formed and rules written. There are one hundred and sixty-odd Rainbows sailing and more are dropping off the production line all the time.
In summary, the Rainbow is by no means as sophisticated a racing boat as the Shields Class (also designed by Sparkman & Stephens), and even though she has a great many good qualities it is still bard to equate her appearance with her designer's name.
JANUARY, 1964 RAINBOW A NEW RACING DAY SLOOP
LOA 2'1' 2"----- LWL 17' 3"-----Beam 6' 3"-----Draft 3' 6"-----Keel (lbs) 1120 Genoa 164'-----Spinnaker 365'-----Sail Area 218'
Three years after her introduction, the 24' Rainbow' is a spectacular success in the world of sailing. There are hundreds of Rainbow's sailing in all parts of the United States, in the Caribbean, in South America and in Europe. Seldom has a new sailboat receded much an immediate response from such a wide area.
These handsome mast-head sloops, deigned by Sparkman and Stephens, have molded, low maintenance fiberglass hulls. The primary thought behind Rainbow's design was to produce a large, comfortable day-sailer which could be raced and which also could be converted to fit the strict Midget Ocean Racing Club requirements.
Drawn with a conventional, graceful sheer and well balanced ends, Rainbow is 24'2" over-all, 17'3" DWL, and she has a beam of 6'1t". She draws 3'6", her draft being gained by an 1120 lb. east Iron fin keel. Her Independent rudder is bronze and fiberglass
Rainbow has room enough for 2 berths plus a head in her cuddy cabin and her 8'5" cockpit with deep seats should be big and comfortable enough to suit most families. She also has built-in flotation and roller reefing is standard. Among other available extras are Genoa, spinnaker (together with gear), head, and other cruising equipment.
The Rainbow is also available in a cruising model for weekending and MORC racing.