Legal in every class. The dimension differs by division.
This page is IJSBA only, and the bodies do not
agree. The same part under UIM. 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.
20 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.
Keep it, but measure it: the rules permit this part only inside stated limits.
Legal, with conditions 20 classes
Extension may not be wider than the OEM plate, sides must be connected and radiused, and no fins, rudders or skegs. Max extension beyond the OEM plate: 100.00mm (3.94 in) Ski and Sport, 177.80mm (7.00 in) Runabout.
Aftermarket pump cover plate / 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.