Bowlines are primarily used for attaching jib sheets to the clew of the jib.
Of course, there are lots of other uses. You can use them for attaching two
lines together, but you can also use a sheep bend for that (which is sort of
like a bowline, but with two different lines).

The one-handed bowline is useful if you're in the water and someone throws
you a line:

1.. Assuming that you are right handed, grasp the line with the left hand
about six feet from the free end; this will take all load off the last six
feet of line.
2.. Pass the slack end around behind your body and grasp the line about
six or eight inches from the end with the right hand palm up.
3.. Lie the right wrist across the top of the line between the body and
the left hand. Leave a gap between the body and the wrist. The palm of the
right hand is now down and the line forms a closed loop around the body.
4.. Push the right hand down and curl it over and around the line so that
the closed right hand is forced back to pass inside the loop next to the
body. The palm is now up and a loop is formed around the wrist. Keep this
loop loose. The end of the line in the right hand is now leading away from
the body parallel with the line coming from the left hand.
5.. Pass the end of the line around behind the line coming from the left
hand.
6.. Flip the end of the line towards the body with the fingers and catch
it with the thumb.
7.. Change the grip on the end so that the right hand now only holds the
very end of the line caught by the thumb.
8.. While holding tight to this end withdraw the right hand from the loop.
Figure 8s are used primary to prevent a line from going through a block,
such as a fairlead, and getting "lost" where you can't easily retrieve it.

Other knots that are useful include:

round turn and 2 half hitches - good for fenders, attaching to a piling
clove hitch - a temporary knot to perhaps let a line dry while hanging
sheep bend - attach two lines of dissimilar diameters
cleat hitch - tie up the boat on a dock, generally to secure a line to a
cleat
reefing or square knot - secure a reefed sail from flapping excessively,
attach two lines of the same diameter
rolling hitch - relieve the strain from a line, so you can clear an override

There are others, but these are the ones I use regularly.

--
"j" ganz @@
www.sailnow.com

"RogueIT" wrote in message
oups.com...
So I can tie a bowline and a figure 8 but I am not sure what their
primary
uses are on a boat.

1. can anyone tell me what they are used for?
2. what other knots should I know and why are these knots used?

Thanks,
Scott