The Ideal 18 keelboat was designed by Bruce Kirby as a strict one-design, accessible to sailors of all ages, weights, skill levels, and competitive backgrounds. The emphasis is on strategy, tactical skills, and boathandling, rather than tuning or special rigging.
Download the Owner's Manual, Rigging, and Tuning Guide (PDF)
The jib is self-tacking and roller-furling. When sailing to windward, the jib has a sheeting angle of about eight degrees. The spinnaker is small for an 18 foot boat, and easily handled by any size forward crewmember; with standard twings, topping lift, foreguy, and Spectra sheet/guy. The spinnaker is stored in a mesh bag on the port side of the cockpit.
No hiking straps are provided or allowed; in fact, sailors are required to keep their legs inside the boat. Because of the no-hiking rule and the heavy keel, a larger range of weights is competitive than in most one-designs. In 5-15 knots, any weight is competive.
Keels and rudders are identical with no fairing allowed, the mast steps and partners locations are fixed, and headstay lengths are the same.
Although the boat can have an 80 degree tacking angle, it is usually better to foot some and let the boat run. This is especially true when the waves build up.
Main trim is more important than jib trim in all conditions. Keep the vang loose in light air. When both crew are sitting on the deck, the vang may be pulled harder to bend the mast and open the narrow slot. Above 15 knots, pull the vang as hard as possible and be prepared to use the sheet agressively. The main likes a tight outhaul. The cunningham is a floating tack. Trim it such that no hardlines radiate from the forward end of the bolt rope in the boom slot. There is no main traveler; a fixed, non-adjustable bridle is placed above the tiller.
The jib is tall and narrow. Typical jib trim is one-half inch to three inches from the clewboard to the traveler block. The clewboard adjusts the lead angle; top hole for 0-3 knots, second hole from 4-8, middle hole for 8-18, fourth hole for 18+. Jib halyard tension and length are non-adjustable.
Because the main is large, bearing off requires mainsheet ease above 12 knots. Agressive ease and trim is fast in puffy conditions. In puffy conditions above 15, it is faster to luff the main and keep the boat driving than it is to feather up; partly because the boat sails at high tacking angles in the first place, and partly because this will keep the boat flatter.
On hoists, the crew moves the pole from the boom to the mast, raises the topping lift, and raises the halyard while the skipper trims the guy back. Dousing is essentially the opposite of hoisting. Take care to make sure that the halyard will run free when uncleated.
During gybes, the crew stays in the cockpit. Most prefer to gybe the main first, then the pole. The skipper trims both the sheet and guy during the gybes, and pulls the guy back on the hoist.
Keep the spinnaker in front of the boat and out from behind the main. If the sail repeatedly collapses despite good wind, trying squaring the pole more and easing the sheet. Ideal 18's surf well, but only plane in more than 15 knots of wind. In heavy breeze if the boat is rolling too much, ease the pole forward and trim the leeward twing to gain more control. Also move aft.
| Sail Control/Technique | 0-4 knots |
5-10 knots |
11-15 knots |
18+ knots |
|---|---|---|---|---|
| Mainsheet Tension (boom to bridle) | ||||
| - Flat Water | 8-12" | 6-8" | 6" | 6-10" |
| - Choppy | 8-12" | 8-10" | 8" | 8-10" |
| Outhaul | ||||
| - Flat Water | 1" eased | tight | tight | tight |
| - Choppy | 1 1/2" eased | 1/2" eased | tight | tight |
| Cunningham (cloth tension at slugs) | soft | soft | small wrinkles | flat (no wrinkles) |
| Vang | 5-10 degree twist | 5 degree twist | tight | very tight |
| Jibsheet (clew shackle to turning block) | 1 1/2 - 3" | 3/4 - 1 1/2" | 3/4 - 1 1/2" | 1/2 - 1" |
| Upper Shroud Tension | 150-180 lbs. | 180-220 lbs. | 220-280 lbs. | 300 lbs. |
| Lower Shroud Tension | hand tight | hand tight+1/2 turn | 165-250 lbs. | 225-250 lbs. |
| Heel Angle | 5-7 degrees | 5 degrees | flat as possible | flat as possible |
| Skipper Position (relative to barney post) | ||||
| - Upwind | 1' in front | athwartship | athwartship | 1' aft |
| - Downwind | athwartship | athwartship | 1' aft | 2' aft |
| Crew Position (relative to shrouds) | ||||
| - Upwind | just aft | 3" aft | 6" aft | 1' aft |
| - Downwind | 3" aft | 6" aft | 1' aft | 3' aft |