View Full Version : OB Tunnels in the Cat Class?

07-10-2018, 10:02 AM
I started this here as I am in a Namba district, but it applies to IMPBA clubs also. Reading the MMEU Nats thread tunnels were brought up and without support numbers wise, were not run. I understand and not offended. People built FE tunnels as they were easy to rig but found out they were also very difficult to drive and stay upright. I enjoy tunnels and their challenges and still want to race them. My question is could they, since they are catamarans, run with the cats in their appropriate class. (P-Q or spec) Local races not records. I see no performance advantage and it might bring out some boats collecting dust. All it can do is add boats. Or tunnel die-hards like myself would run them just because. Opinions?

07-10-2018, 04:05 PM
I am with you, all racing tunnels are cats, and while there may be the odd exception, all the powerboat cats I have seen are tunnels. The only catamarans I see without tunnel hulls are sailing boats which use a trapeze to let the air through and stop them capsizing in gusts when they are running on one sponson.

Calling inshore cats tunnels seems to be an american thing, we call them catamarans here in England as do the UIM who run F1H2O.

While I dont know if it is legal in either USA organisation, I can tell you that we run inshore cats along side offshore cats in the UKs cat class, without any big advantage or disadvantage to either, so there is no need for them to be seperate for good racing.

We have never had an outboard class here so all the inshore cats have a typical inboard motor and rudder with a dummy outboard, which has the advantage of a lower CoG so it can be made self-righting, but the offshore cats are generally much better in the rough and capsize less in the first place. I think you would be racing at a disadvantage if you had a functional outboard on a cat, and more so if it was on an inshore cat.