OEM part required 1 class
Must remain OEM stock, and no aftermarket hull is listed. Interior reinforcement of the OEM hull is answered under hull modification. · W.1, W.7.3
IHRA · Hull and handling
Aftermarket hull, IHRA
IHRA answers this part for 29 of its classes. 1 of those answers permit the part outright and 9 permit it with stated conditions, leaving 19 that do not. 13 are inferred from how the class is written rather than quoted from a rule naming this part.
This page is IHRA only, and the bodies do not agree. The same part under IJSBA and UIM. Which one applies to you is decided by whoever sanctions the race you enter.
Where it stands, class by class
29 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.
What each answer below means
- OEM part required
- This comes off. Only the part the manufacturer fitted is allowed here.
- Not permitted, not listed in the rules
- 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.
- Legal, with conditions
- Keep it, but measure it: the rules permit this part only inside stated limits.
- Legal
- Keep it. The rules permit this part in this class.
OEM part required 1 class
Must remain OEM. NO HULL SWAPPING. Both upper and lower hull must be Sea-Doo. · DD.11
OEM part required 1 class
Yamaha Pro Stock starts from an OEM craft and keeps its hull, so no replacement hull may be fitted, and the work DD.1 allows on it is answered under hull modification. · DD.1
OEM part required 1 class
Sea-Doo Pro Stock starts from an OEM craft and keeps its hull, so no replacement hull may be fitted. · DD.2
OEM part required 1 class
Yamaha Spec starts from an OEM craft and keeps its hull, so no replacement hull may be fitted. · DD.3
OEM part required 1 class
Sea-Doo Spec keeps the OEM hull and top deck, so no replacement hull may be fitted. · DD.4
Not permitted, not listed in the rules 11 classes
On a closed list an unlisted modification is not permitted. · A.2.2, J.1
Not permitted, not listed in the rules 1 class
No aftermarket hull is listed for Ski GP3, and on a closed list an unlisted modification is not permitted. The SuperJet two-stroke extension is answered under hull extension. · A.2.2, J.1
Not permitted, not listed in the rules 1 class
DD.7 lists no replacement hull, and the section DD preamble says "If it is not listed here then it will not be legal". · DD.7
Legal, with conditions 2 classes
Aftermarket hulls may be attached to OEM top decks within the class limits of 97 in length and 20 to 30 in width. A bow appendage is answered under hull extension.
- Ski 1100 Modified · R.1, R.6.1
- Ski 1500 Modified · Q.1, Q.6.1
Legal, with conditions 1 class
CC.1 leaves an aftermarket hull open, but CC.5.1 requires it to be no smaller than the top deck's minimum measurements and joined to the deck by the original method. It may create no safety hazard and may not be tethered or fastened to the rider. · CC.1, CC.5.1
Legal, with conditions 1 class
Aftermarket hulls permitted subject to Race Committee and IHRA approval. No fins, rudders, or skegs. Must not exceed the length or width of the upper deck bond flange by plumb bob. · K.8.1
Legal, with conditions 1 class
Aftermarket hulls permitted with Race Committee and IHRA approval. · V.9.1
Legal, with conditions 1 class
Must be a two-stroke runabout personal watercraft from any manufacturer, jet driven, with surface-drive propellers not permitted. · DD.12
Legal, with conditions 1 class
Must be a stand-up PWC from any manufacturer, jet driven, with surface-drive propellers not permitted. · DD.10
Legal, with conditions 1 class
Must be a PWC. · DD.6
Legal, with conditions 1 class
Aftermarket hulls permitted if approved by the series organizer. Upper deck must resemble the OEM version as closely as possible. Silhouette test settles disputes. · X.7.1
Legal 1 class
Carbon-fibre hulls are permitted, and hulls may be swapped between any manufacturers. · DD.5
Aftermarket hull: 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 IHRA class · where the rulebooks differ · checks on parts the shop sells · how this site reads a rulebook.
Hull and handling · two and four stroke · legal in 10 of 29 answered, 9 with conditions