CENTERBOARD RETAINING PIN

[doug8684]

Now that I've read the posts on potential mods for the centerboard trunk handle, (one with a hand drawing showing a port bump that looks just like my newly acquired DS 1), I have a question. My centerboard and both sides of my trunk have a small hole. It's close to the trailing edge, and is about 1/4" in diameter. It looks like they will line up when the centerboard is lifted all the way up. I already removed my centerboard, so I can't verify this. I assumed it was there so you could lock the centerboard up when trailering, launching, or retrieving. I didn't see any mention of this in the posts, so I'm wondering if it's standard or a PO modification. Seems like a nice safety feature.

[GreenLake]

My guess is something your PO did. I make sure my trailer supports the CB from below with a strategically placed roller. Then the friction/ratchet only has to keep it up during actual launch.

[ThomBlock]

Now that I've read the posts on potential mods for the centerboard trunk handle, (one with a hand drawing showing a port bump that looks just like my newly acquired DS 1), I have a question. My centerboard and both sides of my trunk have a small hole. It's close to the trailing edge, and is about 1/4" in diameter. It looks like they will line up when the centerboard is lifted all the way up. I already removed my centerboard, so I can't verify this. I assumed it was there so you could lock the centerboard up when trailering, launching, or retrieving. I didn't see any mention of this in the posts, so I'm wondering if it's standard or a PO modification. Seems like a nice safety feature.

Those holes are air vents. When the CB is drawn up during a race, one hears the air escape from the void in the truck when the blade is hauled in.

[Fly4rfun]

My DS1 dose not have the a fore mentioned holes .would agree the PO added them

[ThomBlock]

My practical explanation for the holes in my truck.

To clarify after visiting my boat yesterday. I see there are two holes aft of the thwarts near the top of the centerboard truck. Holes are 1/4 inch diameters on both sides of truck. When I am sailing and need to raise of lower the centerboard, I hear the air venting especially when I raise the board. It makes sense to me that air vents allow the air in the truck pocket to escape when the blade is pulled up into the truck. The trapped (displaced) air in the truck void needs to go somewhere.

I'll get a picture of what I am talking about and post it to this thread.

[GreenLake]

why is that needed? what would be the benefit? it's the first time I've heard about that.

I have heard a about attempts to pin the CB in the up position.

[tomodda]

>The holes are there to vent air, that is all.

Curious why one would have to vent air from the CB Trunk? Where is it coming from, considering that the CB slot is underwater? I've got a wooden cap / control console that I've built a-top of my CD Trunk (My DS is from 1958, so has a flat-top CB trunk) and it's held down with thru-bolts going from side-to-side at the very top of the trunk. Very handy, the CB Cap is where I've mounted my mainsheet jammer, spinnaker sheet controls, Vang Lead, and Compass. However, despite lots of silicone caulking, those bolt holes leak like crazy whenever I'm at speed. Water gets forced up into the CB Trunk off the trailing edge of the board, with quite a bit of pressure. One of my Springtime projects is to better seal the bolt holes (good luck), I can't even imagine leaving them open as "air holes!"

On the positive side, it's a built-in speed indicator - if it's dripping I'm at 5ish knots, leaking steadily I'm near 7, spouting water then I'm planing. Look Ma, I'm flying!... no, I'm bailing!... Flying!.. Bailing! It's like sailing an FJ, just more bigger Anyway, overall I'd prefer not to have holes in my CB Trunk. Holes belong in your transom.

Tom

[ThomBlock]

Here's a picture of what I am calling an air vent in the CB truck.
The hole aft of the thwarts on both sides.
It makes sense to me to have positive air pressure inside the truck but what do I know?
I am sure there are folks who have forgotten more than I'll know about the DaySailer.
I am open to other theories.

IMG_2563 (1).jpg (20.33 KiB) Viewed 10629 times

[watchman]

In my opinion, if your centerboard also has a hole drilled through it near the trailing edge that lines up with the holes on the trunk (as per your original post) it is almost certainly for locking the centerboard in the up position.

I'm guessing that the centerboard at some point was loose enough to droop, or even refuse to stay up far enough to allow launching.