vented plugs

Does having a vented plug effect the performance of your boat?I have been paddling with a few of the boys from the local SLSC and the have non vented bungs and actually blow a few breaths into the hull in effect inflating the hull before they go out on the water.On my ocean racing ski it has a vented plug.The boys tell me the thought with inflating the hull pre paddle is to stiffen up the hull.This doesn't seem to be a concern on the ocean ski's.Any thoughts?

I was wondering that myself the other day.
It would be good if a manufacturer would pipe in and reveal the truth.

I would assume that the main advantage of blowing into the vent hole would be to add more air pressure because, if the ski is hotter than the water temp, the air in the ski will cool during the first few minutes of paddling which will drop the air pressure inside the ski to less than atmospheric pressure, the result of which would make the ski suck in water through any pinhole present. Blowing into the ski would simply limit the amount of water that gets sucked in.

A vent will allow air pressure to equalize between the inside and outside of the hull with changes in air temperature (and prevent hull deformation in extreme cases). It also allows moisture to escape from inside the hull. You won't generate enough air pressure blowing into a hull with your mouth to have any significant effect on the stiffness of the boat.

Then why not just have a capillary type vent for all skis then?
No water entry, and pressure equalisation.

Is the straw type just a poor attempt at making a capillary?

I suspect the straw is the simple, cost-effective approach to a capillary.

I'm sure that a universal capillary type vent could be manufactured for cents.
Surely there is a outfitting manufacturer out there that could bring this to the market.

I just drill a hole through the plug and feed a small tube through it. Easy.

As for blowing a few breaths into the boat is a Ye Olde practice which has hung around. Current spec ski manufacturers disuade this as the boats ( vac bagged / infused ) are much stiffer, not to mention you don't want stress the seam. Infact, paddle the boat on a warm day without blowing into it and it release the plug. The air blows out like hell. No need to puff into the thing.

Hey but let us stop that entertaining practice, it gives the clever okes some humour watching 50 guys each blowing a ski.

I have drilled a hole in the bung, the smallest drill bit I have is about 2mm. Admittedly 95% of my paddling is flat or small chop but I have not taken on any water todate. My biggest concern was the problems I had years ago with my wave ski, causing cracks all over when the bung was forgotten in.

My plugs are made from a rubber cork/stopper. Pick up a couple of the right size for your ski. I then drill a small hole through it. The hole pretty much closes up because that's just how rubber is.

I then take a small section of 12 guage electrical wire with the plastic insulation (used in USA houses). I poke the wire through the tiny hole in the stopper. Once the wire is inplace through the stopper I then pull the copper wire from within the plastic insulation. This insulation acts or is now essentially a tiny straw which air can pass through.

The copper wire allows you to insert the "straw". If you drilled the hole the right size the "straw" will stay firmly in place and will not separate from the rubber stopper.

I make a couple of these and keep them around.