In reply to Jayson Keable:
I have worked in climbing walls for years and taught hundreds of beginners how to climb. I discuss the pros and cons of different knots regularly and most especially on Lead climbing courses.
I use a fig 8 most of the time but when working/rushing use a bowline (I know several types all of which are safe when tied correctly). Several of my mates climb on a bowline and when i am with them i might too.
One of the main ways we keep people safe, is to teach, enforce and insist on a 'buddy check', the BMC agrees it works and I don't know a single climber, diver or paratrooper who thinks a 'buddy check' is a bad idea. A buddy check is designed to keep you alive an safe because:
If we assume everyone, including instructors and experienced climbers will make a mistake one time in every 10.000 cos we are all human. one time in 10,000 we might deck or die!
If though, we have two people checking everything, the chances of them both making a one in 10,000 mistake at the same time (climber ties it wrong and belayer fails to check it correctly) are about a trillion to one (I am obviously not a mathematician)
So a buddy check hugely reduces the chances of an incorrectly tied knot.
Given that this thread has decided (and I think in the wall I work in now the percentage is lower) only 20% of people can tie a bowline, thus only 20% of people are able to check a bowline. If you change partner, there is an 80% chance your new partner will be unable to check your knot and your survival rate drops to one in 10,000 (unless you are perfect and do not make mistakes)
I have proven this theory dozens of times when discussing bowlines. At least 80% of customers/students climbing with a bowline user (when asked) could neither tie or check a bowline but every single person without exception was able to tie and inspect a fig 8 correctly.
For this reason alone, I would argue that we should teach beginners the fig 8 and encourage its use generally. I would then teach bowlines as part of a developmental course, discussing it's wider uses and pros/cons.
Its also well known that an incorrectly tied bowline may fail catastrophiclly but you can pretty much retie a fig 8 as incorrectly as you like and it will still hold a fall. After extensive testing we have proven that even if you only put the rope through the first bit of the 8 and do not re-thread at all, it generally still works in a fall and strangles the rope to arrest the fall (don't try this at home without a safety rope).
A fig 8 is never too hard to untie if you can tie it properly with no twists or folds in the re-threading process (most good instructors can do this) and because it is neat it is easier to inspect quickly.
I am a competent bowline user but have to look quite carefully at a bowline to ensure it is safe during a buddy check, a neat fig 8 takes only a quick glance to verify its safety.
Walls are there for your pleasure and to make a profit but want to keep you safe and climbing popular. Not everyone is as clever as some of you guys (work in a wall for a while and meet every type of idiot and half wit) and it is difficult for an instructor/floor walker to know which is which. It is not always easy to allow them time to prove they are competent and takes a lot of time/tact to convince an experienced climber that they have been doing something in a less than perfect manner for years (I have always done it like this and he's not dead yet is common) but trying to explain that all the lemons have to line up at the same time to prove something is unsafe is not always easy.
A fig 8 is quicker to check,
Pretty much everyone is capable of checking it,
It is less likely to fail if tied incorrectly and they can always be untied if re-threaded correctly. i would guess these are the reasons some walls have started insist on their use.
Most walls are still happy to allow any safe knot and employ climbers who know several types of knot.
If you are unwilling to make simple changes (fig 8 instead of bowline) to make life safer and easier for climbing in general, then do not go to the wall that ask you to use a fig 8. If you are unable to tie a fig 8, then ask the wall staff to help you. They are usually friendly people doing a job they like and are keen to help. The woefully inadequate staff get paid a low wage because it is a nice job and do not need obnoxious, arrogant, 'good' climbers being difficult and insulting them because they do not know every single type of knot and can not check them all as easily as they can a fig 8.
Be nice, teach the instructor your fancy bowline, tell him of its pros/cons then use a fig 8 to make life easy for him. It probably was not his decision.