Olson 25 One Design Class Rules
and Boat Specifications
Last modified January 2006
1.0 Construction, Measurements and Equipment:
1.1.1 Intent: Except where variations are specifically permitted within these rules all yachts of this class shall be alike in hull, keel, rudder, mast construction, weight and weight distribution, sail plan, and equipment. The intent of these rules is to promote tight one-design competition rather than development of the Olson 25 sailboat.
1.1.2 Standards: The original plans and specifications as used in production by Pacific Boats, Inc. shall be considered as the official dimensional standards with respect to hull, spars, and rigging.
1.1.3 Interpretation: Specifications, however complete, cannot anticipate every possible situation that may arise. If a point is herein not covered, or if ANY uncertainty exists in an interpretation, a ruling should be obtained from the Rules Committee. In interpreting these rules and specifications, the committee shall consider the intent rather than any other technical construction that might be derived from the wording and shall bear in mind at all times the basic principal of these rules and specifications is to maintain the Olson 25 Class as a one-design class. Nothing is optional in these rules and specifications unless so stated. In the absence of the specific rules to the contrary, the rules of the U.S.Y.R.U. shall apply.
1.2.1 The hull and interior shall be molded in glass reinforced plastic (fiberglass) in the molds originally built by Pacific Boats, Inc.
1.2.2 The interior bulkheads shall conform to the details of Official Plan A.
1.2.3 Prohibited Hull Modifications / Variations: The following hull modifications / variations are specifically NOT permitted:
184.108.40.206 Coring, drilling out, rebuilding, replacement of materials, grinding, or relocating standard equipment in order to reduce weight or improve moments of inertia.
220.127.116.11 Re-shaping any profile or contour.
18.104.22.168 Addition or removal of windows or skin fittings other than those required for the depth sounder, knot meter/log, sink and marine toilet.
1.3.1 The deck and cockpit shall be molded in glass reinforced plastic (fiberglass) in the molds originally built by Pacific Boats, Inc.
1.3.2 The stem fitting shall remain a two horn fitting as supplied by the manufacturer.
1.3.3 The athwartship position of the jib and genoa tracks shall remain as supplied by the manufacturer.
1.3.4 The length and position of the mainsail traveler shall remain as supplied by the manufacturer.
1.3.5 The deck shall be fitted with 24" wire lifelines of not less than 1/8" in diameter as supplied by the manufacturer. The bow pulpit, lifelines, stanchions shall remain the standard height and number.
1.3.6 Allowed Deck Modifications / Variations: The following deck modifications / variations are specifically permitted:
22.214.171.124 Bow pulpit may be extended farther aft and the single forward stanchion may be replaced with two stanchions with the sole purpose of strengthening the pulpit.
126.96.36.199 The standard low stern open pulpits may be replaced with a 24" high, one or two rail full enclosed stern pulpit.
1.3.7 Prohibited Deck Modifications / Variations: The following deck modifications / variations are specifically NOT permitted:
188.8.131.52 Through-deck leads of any control lines.
1.4.1 The keel shall be cast lead in the mold originally built by Pacific Boats, Inc.
1.4.2 Prohibited Keel Modifications / Variations: The following keel modifications / variations are specifically NOT permitted:
184.108.40.206 Relocation of the keel to any position other than the originally specified location by the manufacturer.
220.127.116.11 Reshaping of the keel other than from normal fairing and wet sanding.
1.5 RUDDER AND TILLER:
1.5.1 The rudder shall be molded in glass reinforced plastic (fiberglass) in the molds built by Pacific Boats, Inc.
1.5.2 The tiller shall be made of wood. Tiller extensions are free.
1.5.3 Prohibited Rudder and Tiller Modifications / Variations: The following rudder and tiller modifications / variations are specifically NOT permitted:
18.104.22.168 Relocation of the rudder to any position other than the originally specified location by the manufacturer.
22.214.171.124 Reshaping of the rudder other than from normal fairing and wet sanding.
1.6 SPARS AND RIGGING:
P: 28.00 ft.
E: 10.00 ft.
I: 32.00 ft.
J: 9.60 ft.
The mast shall be an aluminum extrusion that conforms to the mast specifications of the original plans on file with the association and Ballenger Spars (
). No alterations of modifications are allowed except to facilitate the attachment of rigging and fittings as specified within these one-design rules. The mast section shall not be cut-out, lightened, or otherwise modified in any way.
1.6.2 Mast Step:
The mast step assembly shall not be changed or relocated in any way that will change the location of the centerline of the mast.
1.6.3 Main Boom:
The main boom shall be an aluminum extrusion that conforms to the boom specifications of the original plans on file with the association and Ballenger Spars (
). No alterations or modifications are allowed except to facilitate the attachment of rigging and fittings as specified within these one-design rules. The boom section shall not be cut-out, lightened, or otherwise modified in any way.
1.6.4 Main Boom and Gooseneck:
The main boom gooseneck shall not be changed or relocated.
1.6.5 Spinnaker Boom:
The spinnaker boom shall be made of aluminum from any manufacturer with a length not exceeding 9.60 ft. The spinnaker boom shall attach to the mast by a ring either permanently fixed, or on a track / slide mechanism not more than 6 ft. long. (The spinnaker boom may be stowed on the main boom. See 1.11.2)
1.6.6 Standing Rigging:
The mast standing rigging shall consist of one foresta, one backstay and backstay bridle (with or without cascading block and tackle), two upper shrouds, two intermediate shrouds, and two lower shrouds.
126.96.36.199 The standing rigging shall be of 1 x 19 stainless steel multi-stranded cable as originally supplied by the manufacturer or specified by the original plans (Uppers 3/16" dia., Lowers 5/32" or 3/16" dia., Intermediates 1/8" dia).
188.8.131.52 The forestay and shrouds may not be adjusted while racing.
184.108.40.206 The backstay and its' associated adjustment rigging shall be attached to the masthead crane and the two transom mounted tangs.
220.127.116.11 Prohibited Standing Rigging Modifications / Variations: The following standing rigging modifications / variations are specifically NOT permitted:
18.104.22.168.1 Changing the type, length, angle, or method of attachment of the spreaders.
22.214.171.124.2 Changing or relocating the attachment points of the standing rigging to the mast or deck.
126.96.36.199.3 The use of any hydraulic rigging adjusters.
188.8.131.52.4 Altering or replacing the tensioning devices of the headstay or shrouds.
1.6.7 Running Rigging: The running rigging consists of the following:
184.108.40.206 Two Forward Jib / Spinnaker Halyards: The two forward jib / spinnaker halyards can be of any material and shall exit from the masthead and mast step fittings supplied as standard equipment from the manufacturer. Modifying the mast to allow the spinnaker halyard to exit above the mast step is specifically discouraged, as the manufacturer has indicated that such a modification will weaken the mast. The spinnaker halyard shall not be jumped from the mast during one design racing.
220.127.116.11 One Mainsail Halyard: The mainsail halyard can be of any material and shall exit from the masthead and mast step from fittings supplied as standard equipment from the manufacturer.
18.104.22.168 One Spinnaker Boom Uphaul: The spinnaker boom uphaul shall be of any material and shall exit from the masthead and mast step from fittings supplied as standard equipment from the manufacturer.
22.214.171.124 All Other Running Rigging: All other running rigging unless specifically mentioned as prohibited or illegal modifications, may be relocated, deleted, or substituted.
1.7.1 Use of Sails During One-Design Events: Unless otherwise specified by the race instructions of a specific event, only one of each of the following four sails may be used during a San Francisco Bay Area one-design regatta, or National Championship:
3. 95% Jib
All sails must comply with the requirements and specifications of that sail type within the rules. Compliance is the ultimate responsibility of the boat owner, not the sail maker. Alteration, repair, or replacement of a damaged sail during a regatta is allowed provided:
1. The damaged and the replacement sail are submitted for inspection to a Rules Committee member as soon as possible after the race in which the damage occurred.
3. The Rules Committee member approves the replacement.
1.7.2 New Sail Purchases: No more than four sails may be purchased during any 24 month period.
1.7.3 New Sail Measurement and Registration: At the time of completion, the constructing sail maker shall measure the sail using I.O.R guidelines. The constructing sail maker shall sign the sail itself with the corresponding date of the measurement record.
126.96.36.199 Girth Measurements:
188.8.131.52.1 The maximum mid girth is measured from the mid leech to the nearest point of the luff, including the luff rope: Maximum Mid Girth=4.0 ft.
184.108.40.206 Maximum Leech Length=30.00 ft.
220.127.116.11 Four battens approximately evenly spaced up the leech of any length.
18.104.22.168 Maximum Fore and Aft length of the headboard=4.75 in.
22.214.171.124 There are no restrictions on sail material, except that in San Francisco Bay Area one design competition, mainsails must be constructed of Dacron. 126.96.36.199 The Olson 25 Class Emblem shall be displayed on both sides of the mainsail between the top two battens.
188.8.131.52 The hull number, or an assigned number, which conforms to the I.Y.R.U. requirements shall be displayed on both sides of the mainsail.
184.108.40.206 Girth Measurements (Taken for I.O.R.): The mid girth measured between the mid points of the luff and leech, shall not exceed 50% of the foot length nor shall the length of the intermediate girths at 25% and 75% of the luff and leech from the head exceed values similarly proportioned to their distance to the head.
220.127.116.11 L.P.=14.69-14.88 ft. (2% tolerance) measured from the forward edge of the luff tape to the extension of the clew.
18.104.22.168 Any material may be used.
22.214.171.124 The hull number, or an assigned number which conforms to the I.Y.R.U. requirements, shall be displayed on both sides of the genoa.
126.96.36.199 Girth Measurements (Taken for I.O.R.): The mid girth measured between the mid points of the luff and leech, shall not exceed 50% of the foot length nor shall the length of the intermediate girths at 25% and 75% of the luff and leech from the head exceed values similarly proportioned to their distance to the head.
188.8.131.52 L.P.=8.93-9.12 ft. (2% tolerance) measured from the forward edge of the luff tape to the of the clew.
184.108.40.206 Any material may be used.
220.127.116.11 A reef is allowed.
18.104.22.168 There may be up to four battens evenly spaced.
22.214.171.124 Luff Length-30.12-31.70 ft.
126.96.36.199 Girth: Maximum Girth (at any point)=17.28 ft.
188.8.131.52 There are no restrictions on materials, except that in San Francisco Bay Area one design racing, material used in making the sail shall be rip-stop nylon with an actual weight no lighter than 36 grams per square meter.
184.108.40.206 The hull number, or assigned number which conforms to the I.Y.R.U. requirements, shall be displayed on both sides of the spinnaker.
1.8 FIXED FITTINGS AND EQUIPMENT TO BE CARRIED WHEN RACING:
1.8.1 Two primary sheet winches located on the cockpit coaming.
1.8.2 Berths equipped with cushions as supplied by the manufacturer.
1.8.3 All interior parts and assemblies as supplied by the manufacturer. However, "Porti-Potti" and Stoves may be removed.
1.8.4 Companionway boards as supplied by the manufacturer.
1.8.5 One securely mounted 12 volt battery of not less than 40 amp/hour capacity.
1.8.6 Permanently installed navigation lights in working order.
1.8.7 A fixed marine type compass of magnetic card or digital readout.
1.9 ADDITIONAL SAFETY EQUIPMENT:
The following equipment must be on-board while racing:
1.9.1 Outboard motor and fuel: An operable outboard motor with a minimum of 3.5 horsepower and fuel tank which when filled has a combined weight of 45 lbs. or more.
220.127.116.11 Outboard motor fuel may not be stored inside the cabin.
18.104.22.168 The outboard motor must be stored on the post under the cockpit sole or may be mounted on the transom during one-design racing.
1.9.2 A manual bilge pump.
1.9.3 At least one water resistant flashlight in working order.
1.9.4 A U.S.C.G. approved fire extinguisher.
1.9.5 U.S.C.G. approved life jackets for all crew members.
1.9.6 One horseshoe life-ring.
1.9.7 One fog horn.
1.9.8 A U.S.C.G. approved Visual Distress Signal kit.
1.9.9 An anchor (minimum 8-S danforth or equivalent) with at least 150 ft. of 3/8 in. anchor line.
1.9.10 Charts and plotting equipment.
1.9.11 Sailing instructions from any sailing event may prescribe additional safety equipment.
1.10 OPTIONAL EQUIPMENT:
1.10.1 Barber haulers for the jib, genoa, and spinnaker sheets.
1.10.2 Two secondary winches mounted on top of the cabin.
1.10.3 One headstay luff groove device not exceeding .12 in. in width.
1.10.4 Any type of electronic / mechanical knot-logs or depth sounder.
1.10.5 The use of genoa or jib roller furling equipment when racing.
1.10.6 Barney Post used for the purpose of securing the mainsheet.
1.10.7 A VHF radio IS STRONGLY recommended.
1.10.8 A solid boom vang, or boom kicker
1.11 PROHIBITED OPTIONAL EQUIPMENT:
1.11.1 Running backstays.
1.11.3 Masthead anemometer driven electronic instruments.
2.1 A crew shall consist of not less than three and not more than six persons. In Regional Championships or the North American Championship Regattas, the number of crew must remain the same throughout the event.
2.2 The total crew weight shall not exceed 962 lbs. in street clothes without shoes.
2.3.1 In any race recognized by the association, except the Class National Championship, the helmsman must be the owner, a charterer, or a similarly qualified substitute. If a substitute is used, his/her skill level shall NOT result in any advantage over the owner-driven boat. The onus of a protest shall be on the protested boat. Only a majority of the Rules Committee can adjudicate a protest to this rule.
2.3.2 In the Class National Championship only the owner or a person who has chartered a boat for the entire event may drive the boat.
2.4 Crew Rule and Guidelines:
2.4.1 When equipped with double lifelines, the crew may sit with their torso outside the upper lifeline, however the lower lifeline must be of taut wire.
2.4.2 On boat equipped with 24" stern pulpits, the helmsman may sit outside both lifelines.
3.0 RULES ADMINISTRATION:
3.1 Rules Committee: The Rules Committee, chaired by the Director-Rules and Specifications, shall be appointed immediately after each annual meeting by the President. Its members shall hold office for one year. It shall pass on all questions relative to eligibility of boats and equipment, interpret the rules and specifications, and recommend to the governing committee of the association any advisable alternations or additions to the class rules.
3.2 Initiating a Change of the Rules: Any member of the association may make suggestions, complaints, proposed changes of the rules in writing to the Director-Rules and Specifications. However, the Rules Committee only, has the power to initiate an official change of the one-design rules.
3.3 Changes of the Rules: If the Rules Committee decides to change the rules, the Rules Committee must pass the proposed change on to the governing committee. The governing committee will is
a proxy vote on the new proposed rules to all association members. For a rule to be adopted, a 2/3 majority vote is required of all returned proxy votes.