Hi Framey .
I've recently used the small Plumb-Ezee ( with a dumpy pear ! ) and it certainly pops up to the surface locked to the depth it has found .
However , it seems that it will still come to the surface even if it lands in the middle of a weedbed . What I did notice though was that sometimes when it surfaced bubbles erupted around it , so maybe that's where the weed is ? .
I'll have a twiddle , then it should be just the job .
😃