Aftermarket seat assembly / seat base

Runabout and Sport only in practice.

The Seat Appendix adds hard limits wherever aftermarket seats are legal: front may not protrude more than 1 in over the top deck vs OEM, knee/leg cradles must be entirely soft flexible material cradling no more than 50%, no hard material over the leg or knee, no velcro or adhesive binding the rider, and a rear height cap of riding-height x 0.30.

Where it stands, class by class

12 classes, grouped by the answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules.

OEM part required 1 class

OEM SEAT BASE MUST BE USED. Cover change allowed; height +/-12.7mm (0.5 in); cover adds no more than 0.5 in thickness.

Runabout Rec Lites · RRL

OEM part required 1 class

OEM seat base required. · RAS.2.10

Runabout Stock

OEM part required 1 class

OEM stock seat base required. Height may be changed and/or covered.

Sport Spec · none - this document uses ALL-CAPS section headings, not numbered rules

The rules do not say 1 class

No seat-height limit surfaced.

Vintage Ski · VSK

Legal, within limits 1 class

Two-stroke: OEM base required. Four-stroke: aftermarket seat assembly per the Appendix.

Runabout Naturally Aspirated · RNA

Legal, within limits 1 class

Seat covers and assemblies modified or aftermarket, with seat height no more than 3 in above original.

Vintage SC · VSC

Legal, within limits 1 class

Seat covers and assemblies modified or aftermarket, with seat height no more than 10 in above original.

Vintage X2 · VX2

Legal 1 class

Aftermarket seat per the Appendix provisions. The Stock OEM-base requirement is lifted. · RAL.2.10

Runabout Limited

Legal 1 class

Aftermarket seat assembly, height may be modified. · RSS.2.10

Runabout Superstock

Legal 1 class

Sport and Runabout seat assembly modified or aftermarket. Presence of a seat classifies the craft as Sport or Runabout by dimension.

Freestyle · FREST

Legal 1 class

SPGP.3.10

Sport GP · SPGP

Legal 1 class

ROP.3.10

Runabout Open / GP · ROP

Aftermarket seat assembly / seat base: if the rule your class applies reads differently to you, or the rulebook has changed since this was read, ask. We answer with the section we read it from, or that we have not read it. Ask a rules question.

Every IJSBA class · where the rulebooks differ · signed checks on parts the shop sells.

Hull and handling · two and four stroke · legal outright in 8 of 12