Played my shot which went into the woods at the back of the green. I found my ball and had a shot out. I asked my playing partner whether it was out of bounds and he noticed a white post about 15 yards to my right. I took it as OOB but when I thought about it later, there was only 1 white post. I now wonder if there should be more than 1 white post to determine the line of OOB.

Was I wrong in taking a drop?

Yes..There should be more than 1 post

Yes..You were wrong to take a drop.  If the ball was OOB you should have gone back to where you played your last shot from and impose the penalty for going OOB 

this is a little grey area

i would have said you were fine and shouldnt have taken a drop whereas others may have said it is OOB and you should have gone back to where you played your last shot

in an event recently i hit my approach shot left into a course boundary hedge, now under the course's local rules "OOB if beyond any boundary fence or hedge".

now heres a little grey area, was my ball classed as being OOB?

i say not as it was not BEYOND the hedge it was in it, there was also NO white stakes which denotes OOB

You muppet, Millichump..If the local rule says the boundary fence is OOB then there won't be any white posts

i was just explaining all cicumstances marshall snr (very snr)

 and marshall you still havnt answered my question

you answered it yourself....

If it's in the hedge and not over the hedge and is not marked by a white line or with white marker posts its not OB and  is in play.

what about if its on top of the hedge dave?

Matt, that is considered good fortune as it is tee'd up ready for you.

Well Matt that would be easy for you to play being spiderman but not so easy for me the big fella   2 clubs legths,no nearer the hole 1 shot penalty .

I once saw Ernie hit a shot from half way up a bush and make par.

It landed on top of the hedge which was above shoulder height so I took a picture and paid for a drop and carried on, couldnt do it again if I tried I'm sure.

I'd love to have seen that bush Leyo