Sealing the Hull CB slot

[DSGregLS]

Hi, it is quite commonplace in Australia to fix a slotted tape along the opening of the CB case of dinghies, flush with the underside of the hull. This tape is quite rigid but split along its centre so that when the CB is lowered it fits quite tightly and therefore greatly reduces the amount turbulence and pressure inside the CB case. It also reduces the drag of the hull.
Does anyone have experience fitting such a seal on a Daysailer?
Cheers Greg

[GreenLake]

The class rules state in section 5.11

Any form of gasket in the trunk opening is prohibited.

Because of that, only people who don't intend to race under class rules would attempt this modification.

Your CB is already not class-legal, so I'd say why not. I have that system on a different dinghy and seems to work fine there. That is, I can attest that it doesn't impede the deployment of the CB, but I couldn't tell you how much of a difference it makes. I suspect some, otherwise the class rules wouldn't have taken the trouble to rule it out, but probably small enough that you might need to have a boat against boat comparison to see the difference.

[DSGregLS]

Again Thanks GreenLake, I have sealed the top of my CB case and left just a 6mm hole for the CB uphaul to exit in an attempt to reduce that 'squirting' that others have spoken about. I thought that 'gasket' might also help with that problem.
Cheers, Greg

[GreenLake]

I think a gasket will probably reduce the amount and force of the water swirling in the CB trunk, but might not be enough to totally eliminate all dynamic pressure differences. In any case you should see some slight gain in boat speed.

Your 6mm hole, unless you have some gasket or nipple, will transport unbelievable amounts of water -- I've seen that in action.