UIM · Hull and handling

Aftermarket seat assembly or seat base, UIM

Runabout only. UIM's seat ladder is the clearest GP4-to-GP1 progression in the book.

This page is UIM only, and the bodies do not agree. The same part under IHRA and IJSBA. Which one applies to you is decided by whoever sanctions the race you enter.

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This is one body's answer, not the sport's. You are bound by whichever body sanctions the event you enter. If you race more than one series, build to the stricter answer. The differences are set out in the rulebook comparison.

Where it stands, class by class

15 classes, grouped where the same rule gives the same answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules. 3 of them borrow another class’s rules and are marked below; for those, the link to the parent class is read from the categories table rather than stated in the rulebook. 8 publish no rule for this part and name no parent to borrow one from, and are grouped together at the end.

What each answer below means

OEM part required

This comes off. Only the part the manufacturer fitted is allowed here.

Legal, with conditions

Keep it, but measure it: the rules permit this part only inside stated limits.

No rule published for this class

Unanswerable here. This class publishes no rule for the part and names no parent class to borrow one from, which is an absence in the rulebook and not a permission.

OEM part required 3 classes

THE WHOLE ORIGINAL EQUIPMENT SEAT for that model and type must be used. · 502.01.02-12

• Runabout GP4
• Runabout Juniors GP4 · borrows another class
• Runabout Ladies GP4 · borrows another class

OEM part required 1 class

The ORIGINAL EQUIPMENT BASE for that model and type must be used - a relaxation from GP4, which requires the whole seat. · 502.02.02-11

• Runabout GP3

OEM part required 1 class

Original base only, via GP3 inheritance.

• Runabout GP2 · 502.03

Legal, with conditions 2 classes

Aftermarket, modified or PROTOTYPE seats permitted. Must respect the structure and measurements of those available on the market for pleasure-navigation homologated PWC. The base must be well consolidated as it is the divider between the engine compartment and the seat. Seat height may be modified up to 10% from the original model. Back rest height max 18 cm with rider seated. · 502.04.03

• Runabout GP1
• Runabout Veterans GP1 · borrows another class

No rule published for this class 8 classes

No component rules are published for this class and no single parent class is named, so this part cannot be answered for it. That is an absence in the rulebook, not a permission.

• Endurance · 317.03
• Freestyle Amateur · 312
• Freestyle Free · 312
• Jet Raid · 317.01
• Offshore · 317.02
• Parallel Slalom · 313
• Ski Future Electric (SFE) · 302.01
• UIM Hydro-Fly · 900

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Aftermarket seat assembly or 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 UIM class · where the rulebooks differ · checks on parts the shop sells · how this site reads a rulebook.