what are these holes for ??? - ANSWER

[Alrob]

Mystery solved !!!!!!!!
http://www.ybw.com/forums/showthread.php?t=231545


located the end of the port pipe, it goes into a Y piece at the bilge pump hose outlet- strange setup !!!!!!!!

 

[jfm]

Wierd! There must have been a drain problem (puddle) in that deck location, I guess

 

[hlb]

But saves more holes in the boat.

 

[fireball]

Just don't get the y Valve the wrong way and operate the pump .... unless you want fountains out of the sidedecks - could be handy if welcoming home some vessel - like the tugs do ....

 

[DAKA]

The owner could have been attempting to direct air under the hull in an attempt to increase performance, if the seacocks were left open while underway then suction would certainly direct a lot of air under the hull.

I am not suggesting this would increase performance , just suggesting that the previous owner possibly tried this.

 

[jfm]

if the seacocks were left open while underway then suction would certainly direct a lot of air under the hull.

I have no idea what you're smoking there Daka but I'd sure like to try some

 

[DAKA]

I have no idea what you're smoking there Daka but I'd sure like to try some

I didnt say it would work

There are a few boats designed now with advanced aerodynamic/hydrodynamic designs which are supposed to force air under the hull which is claimed to increase lift and reduce drag.

If the above system is opened while at sea air will be sucked under the hull, haven't you ever gone for a pee at 25 knots and seen how your bog sucks

I accept its a daft idea but the set up as pictured above isn't exactly main stream

 

[jfm]

If the above system is opened while at sea air will be sucked under the hull, haven't you ever gone for a pee at 25 knots and seen how your bog sucks

The bilge pump discharge is above the w/line

 

[Alrob]

yes your principle sounds correct but on this occasion the bilge/drain outlet is above water level

cheers