Sorry if this is not cool but I've borrowed a photo from the forum (sabydent's thread) to ask what knot this is and how one would go about tying it?
jskdog,
The two on the boom are prusik knots the other is a reverse, left handed or one handed bowline.
Kaonaona,
Just to be pedantic. What is refered to on the chart as "two half hitches" is actually a "round turn and two half hitches".
What is refered to as a square knot is also a reef knot and when tied another way is known as a thief knot.
And I like to be pedantic.
If any of these are tied in ragged rope they become a-fraid not. 
Too funny! TP1,
Why not just use pad eyes or regular block hangars?
Here is a knot for joining two lines or making a loop, nearly impossible to untie when tensioned.
Thanks for the replies folks, I took the 'new' yacht for it's, and my first ever sail, didn't see these replies so just tiesd a knot in the end to act like a stop....crued yes, but it held up.
The knots on the boom were pruisik hitches. The knot is a slipped knot bowline. (Tied correctly) I now use Landyachts knot to attach my line to the block.
prusiks are great, they just hang on . ive dangled out of the occasional palm tree with my ladder swung out of reach on the odd prusik or 2
This might help too...
www.seabreeze.com.au/forums/Land-Yacht-Sailing/General/Knots/
Why not just use pad eyes or regular block hangars?
If you use knots like the prussic you can easily adjust the position, also use much lighter tube for the boom as the load is not on rivets which might pull out.
And rope is cheap! A strong consideration for most
