IJSBA is pleased to release the draft of the aftermarket seat policy for Runabout Watercraft.  This draft is being circulated for peer review.  Any revisions will be submitted to the IJSBA Technical Director for comments and then sent to the IJSBA Board of Directors for ratification.  The draft is below.  Please send questions or comments to info@ijsba.com.  

The front of the complete aftermarket seat may not protrude more than one inch over the top deck than the original OEM counterpart seat.  Aftermarket seats are limited to how much of the forward portion of the rider may be cradled and are limited to a maximum height of the rear portion.  Any concave shapes that cradle the knees or legs of the rider must be of entirely soft flexible material.  The concave may cradle the knee or leg by no more than 50% prior to compressing the soft material.  Absolutely no part of the leg or knee may be covered by hard material or material that is not flexible.  The seat material may not interact with any surface on the rider (including wetsuit, knee guards, braces, etc.) to create a binding of the rider to the seat (i.e. Velcro, adhesive, etc.) outside of normal friction.

To determine the maximum height of the rear portion of the aftermarket seat the following steps shall be taken:

1.       The rider will fully upright sit on a hard surface chair

2.       The half point between the outside of the rider’s shoulder and the edge of the rider’s neck shall be noted as the “upper point.”

3.       The inspector shall measure between the upper point and the surface of the chair shall be measured.  This shall be noted as the riding “height.”

4.       The riding height shall be multiplied by .30 (30%).  This shall be rounded up to the nearest ¼ inch and shall be the maximum height of the seat section that contacts the rear portion of the rider.

5.       The maximum height shall be measured from the lowest part of the seat.  One half inch tolerance shall be allowed.

6.       The lowest point of the seat may be only one half inch lower than the OEM counterpart of this seat.

7.       A rider found to have any bladder or other such device that allows the height of the lowest seat point to be adjusted shall be disqualified.


At the time of this printing ALL OEM runabout seats are deemed legal with a seat cover that does not change any part of the original shape or thickness by more than one half inch.










Measuring the very top of the section between the outside shoulder and neck to find the hallway point 










The distance from the surface of the seat to the top of the rider's shoulder at the halfway point is take (on this rider it is 24 inches rounded up from approximately 23.75 inches)










24 inches multiplied by .30 results in 7.2 inches











Using the lowest point of the seat a measurement is taken using the figure determined from the method above.  In this case, the distance is 7.2 inches with an additional tolerance of .5 inches.  The rear portion of the seat may rise 7.2 inches from the lowest point.  This OEM seat is well within that allowance.







Notebook: This OEM seat consists entirely of soft material over the area of the rider's knee and leg.  Additionally, the area of the seat is will within the 50% allowance for covering.  No part of this seat assembly holds the rider in place.