IJSBA is pleased to announce revised pending rule changes, to the 2018 IJSBA Competition Program.  IJSBA remains grateful for  comments, contributions, and suggestions we have received- even ones that came well after the published comment window.  This posting will note where previous pending rules have been updated. 

These rule changes will be mailed to the IJSBA Board of Directors for ratification with an expected result posted within seven days.  

Please send any questions or requests for clarification to info@ijsba.com.  

*Revised Sport Spec

  Sport Spec watercraft shall be afforded a second set of sponsons.


  1. Runabout Stock:  Aftermarket Valve Retainers to be allowed
  2. Runabout Limited: No Changes
  3. Runabout Open: To Be Replaced With Superstock and Runabout Open to be merged with Runabout Modified/GP
  4. Runabout Modified/GP:  No Changes



Runabout GP/Modified will continue to exist and shall be a class offered on Saturday at the 2018 IJSBA World Finals.  Sunday will offer Runabout Superstock which shall consist of a Limited Class Runabout with the following additional provisions:  aftermarket hood, aftermarket forced induction system.


SKI * Ski Modified Revised and Ski GP Separated

  1. Ski Lites:  No Changes
  2. Ski Stock: No Changes
  3. Ski Limited:  No Changes.  Ski Limited will be kept as a class description in addendum.  However, in most cases, especially at World Finals, Ski Limited will be replaced with the newly created Mod Lites
  4. Ski GP:  Ski GP is a class that allows two stroke engines, up to 1300cc, naturally aspirated four stroke engines up to 1100cc, and forced induction four stroke engines up to 900cc.  All configurations allow full modified rules.  IJSBA reserves the right to require blow off valves and speed restriction devices to forced induction Ski watercraft in this category.
  5. Ski Modified:  Ski Modified is a Pro Level and Expert Level class for 2018.  Ski Modified allows all eligible Ski GP watercraft as well as all eligible Ski Superstock watercraft.  Forced induction four stroke units may have displacements up to 1100cc.  Turbocharged/Supercharged Ski Watercraft above 900 CC will absolutely be required to run an IJSBA approved speed control device and an IJSBA approved blow off valve. Until these devices are approved by IJSBA, forced induction Ski, with displacement above 900cc should be scored separately at IJSBA Sanctioned events.  
  6. Ski Superstock:  Ski Superstock is intended to be a class that services, primarily, the existing 2018-2019 Kawasaki SX-R.  Ski Superstock allows all provisions of Ski Stock plus the following additional provisions:  aftermarket exhaust, aftermarket throttle body, head porting, aftermarket camshafts, aftermarket valve systems, aftermarket hood, aftermarket ECU, aftermarket propulsion pump, aftermarket water routing.  



Ski Mod Lites will begin in 2018 as a pilot program intending to create a class that services the aftermarket industry and the competitors who wish to engage in aftermarket based performance while maintaining the costs and speeds traditionally associated with mid-level Ski performance.  Competitors may use aftermarket hulls in most circumstances.  Competitors may use two stroke or four stroke homologated engines.  This class is a developing class which is expected to evolve over the next coming years.  Mod Lites will, generally, replace Ski Limited.  Junior 13-15 Limited will change to Junior 13-15 Mod Lites immediately upon the ratification of Mod Lites rules.

1. At the outset of Mod Lites, all immediately eligible engine packages may be affixed to an aftermarket hull that was eligible for the 2017 Modified class.  By the end of 2018, hull manufacturers and hull owners must participate in the IJSBA Aftermarket Hull manufacturing and monitoring system.  This will require affixing IJSBA approved hull identification numbers and maintaining a chain of custody and history of the aftermarket hull.

2.  Competitors who choose to utilize a two stroke engine in Mod Lites may select from any OEM homologated engine that was offered by the original manufacturer of a homologated Ski Watercraft (Yamaha Superjet/Kawasaki 750/SXR).  These configurations will be entitled to all engine, hull, electronic, and propulsion privileges originally afforded to the Ski Limited classes.  IJSBA will begin testing a configuration of allowing a triple cylinder two stroke engine to be affixed to an OEM hull by means of a bed plate with Lites Rules applied to the additional modifications.  However, this is not an approved package at this time.

3.  Competitors who choose to utilize a four stroke engine in Mod Lites may select either a Sea-Doo 900 ACE engine or Yamaha TR1 1050 engine.  If a competitor chooses a Sea-Doo 900 ACE, the engine is restricted to Rec-Lites rules plus the allowance of an aftermarket camshaft and aftermarket valve system.  If a competitor chooses a Yamaha TR1 1050 engine, the competitor must adhere strictly to Rec-Lites provisions.  In either case, the competitor must use all OEM ECU and electronic systems from the original OEM engine package selected.  Aftermarket pump systems shall be allowed.  Competitors may use Hydrospace S4 watercraft to previous Stock Class specifications.


Any other suggested rule changes for 2018 failed to receive any adequate support to be included in the new competition program.

Please send any questions or comments, immediately, to info@ijsba.com.  

Notices for 2019 * Revised

Runabout Competitors please note the following changes planned for 2019:


Stock:  No changes.  Speed control devices planned to limit this class to 70 MPH.

Limited:  This class is planned to change to Stock Class plus only the following provisions: aftermarket camshaft, aftermarket valve system, aftermarket supercharger impeller, aftermarket propulsion pump.  Note this is a removal of aftermarket seats and aftermarket ECU (OEM ECU reflashes still allowed).  Speed control devices are planned to limit this class to 75 MPH.  Cradled seats are not allowed in Runabout Limited.

Superstock:  No changes.  Speed control devices planned to limit this class to 80 MPH.  Cradled seats are not allowed in Runabout Limited.

GP/Modified: No changes.  This class will continue as currently existed so that ultra high performance Runabouts with aftermarket hulls and exotic power systems may continue to showcase the height of engineering and athleticism.  


Expected Class List For 2018 World Finals:

Pro Classes

Pro Ski Modified (Sunday Class)

Pro Runabout Superstock (Saturday Class)

Pro Freestyle  

Pro Am Classes

GP Ski  (Saturday Class)

GP (Sunday Class)

Runabout Stock

Runabout Naturally Aspirated Stock

Runabout 1100 Superstock  (800cc Maximum for Two Stroke, 1100cc Maximum for Four Stroke)

Ski Stock (2017 Kawasaki SX-R is permitted without a restrictor plate)

Womens’ Ski 

Ski Lites

Ski Mod Lites

Runabout Limited

Endurance Runabout Open

Expert Classes

Expert Ski Modified 

Expert Ski Stock 

Expert Runabout Superstock

Expert Veteran’s Runabout

Amateur Classes

Amateur Freestyle 

Amateur Ski GP 

Amateur Ski Lites 

Amateur Ski Mod Lites


Amateur Veteran’s Ski Stock (Two Stroke Limited Legal Ski allowed- this year only).

Amateur Veterans Ski GP  

Amateur Runabout 1100 Superstock (See Open Class Rules, 800 CC Limit For Two Stroke)

Amateur Runabout 1100 Limited (Up To 1100cc Normally Aspirated Four Stroke, 800 CC limit for Two Stroke)

Amateur Runabout 1100 Stock (Four Stroke Powered Runabout Only: Sea-Doo Spark; Yamaha EX)

Amateur Runabout Rec Lites

Amateur Women’s Ski Lites  (All participants who hold an Expert License, All participants who have had a World Finals podium finish in Novice Women’s Ski, and participants who have participated in Pro Am Women’s Ski must petition IJSBA for eligibility in this class).

Amateur Runabout Limited

Novice Classes

Novice Ski Stock 

Novice Ski Limited

Novice Runabout Stock

Novice Runabout Naturally Aspirated Stock

Junior Classes

Junior Ski 10-12 Stock (2017 Kawasaki SX-R Allowed only with IJSBA approved restrictor plate)

Junior Ski 10-12 Lites (Stock Rules 2 Stroke Only)

Junior Ski 13-15 Stock (2017 Kawasaki SX-R Allowed only with IJSBA approved restrictor plate)

Junior Ski 13-15 Lites (Stock Rules 2 Stroke Only)

Junior Ski 13-15 Mod Lites


Other Classes Open To All Skill LevelSport GP

Sport Spec (All Skill Level, Pro Ranked Competitors Must Petition To Participate)

Classic Ski Two Stroke Limited  (Limited Class Rules, Two Stroke Only)

Master’s Ski GP  (2017 Kawasaki SX-R is not allowed in this class.  No displacement above 1300cc.  Forced induction Ski are limited to 950cc)

Master’s Ski Stock (2017 Kawasaki SX-R allowed to Stock Class specifications Only, Two Stroke Ski allowed to Limited Class specifications- this year only)

Vintage Ski (Two Moto’s- Combined Score for Overall)

Vintage X2 (Two Moto’s- Combined Score for Overall)

Women’s Runabout (Limited Class Rules For Two Stoke, Stock Rules For Four Stroke Plus Aftermarket Seat Allowance)

Ski Endurance  Sprint (2017 Kawasaki SX-R Allowed to Stock Class Specifications)


Ski Modified

Runabout Open

Sport GP

Four Stroke Ski Stock