Be aware Bowlines can and do fail. A Bowline can, under certain circumstances fail into a slip knot:

From: Bowline Stability

“The Secret Flaw of a Bowline
Many people are surprised that their beloved Bowline has a secret flaw. It holds securely when arranged and applied in the normal way, with the standing part attached at one end and a weight suspended from the loop at the other end. But jerking the tail of a Bowline to one side can deform it, just as with a Square Knot. If you happen to snag it so that the tail and the right leg of the loop are yanked hard in opposite directions, the structures may not be stable enough to resist deformation. The bight will straighten out and disappear. The hitch that circles the bight will be transformed into a slip knot which has little squeezing power- as well as little to squeeze against. The deformed hitch will not be able to create enough friction to hold and can be easily stripped off. Every time I demonstrate this phenomenon to a group, someone responds "Wow," and someone else calls out "Do that again." “
Additional Info:

Bowline Security

Bowline Breaking


If using a Bowline add a single or better yet a double overhand knot with the running end to the loop part, just above the primary knot (part “L” of the diagram) and snug it against the primary knot.

Pete