Rear extensions, bow appendages and planing surface extensions added to the hull. Pump cover plate extensions and trim tabs have their own rows.
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.
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.
Below GP1 the only rearward addition UIM allows is the pump cover plate extension, which has its own row.
24 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.
8 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.
Treat it as coming off. The class requires the craft to stay stock except where the rules allow otherwise, and this part is not on the list, so this is our reading rather than a rule we can quote at you.
No rule, this is an open class
Probably keep it. The class carries no stock clause at all, so anything unlisted appears to be open. The rulebook does not say so in terms, and this is our reading rather than a permission anybody wrote down.
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.
Not permitted, not listed in the rules 11 classes
Not listed in this class. Illegal under the class's own stock clause.
No article limits an extension to the hull, so under the open-list reading of GP1 one is free inside the 280 cm overall length, and trim tabs may reach 100 mm past the transom. · 501.04.01-03, 501.04.02-05
No article limits an extension to the hull, so under the open-list reading of GP1 one is free inside the 360 cm overall length (394 cm for Endurance), and trim tabs may reach 100 mm past the transom. · 502.04.01-03, 502.04.01-05, 502.04.02-05
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.
Hull extension: 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.