Hmm that is tough when you have more than one 'wee' one cause it gets hard to spot them all than specially if they have not spent a lot of time climbing and do not know the 'safe way' to use the climbers ~ I guess in that case I would either have them taking turns 'confined' so that I could spot them one at a time ... so put the others in a swing or in the stroller with some tray toys and than rotate them out to take turns to get competent in climbing?

It is amazing how quickly kids become competent when they are given time to practice though .... personally just let my little ones do their thing and just 'shadow' to spot when they are on climbers ~ generally with regards to playgrounds every infant I have had was already competent at the stair style ladders and crawls across, turns around and slides down slides by 13 months of age ~ they learned quickly that you do not dawdle at any 'openings' in the climber or you get REMOVED from it and so forth and I just 'redirect' them from certain areas that I do not feel comfortable with them using yet by telling em 'you need to grow a little taller to reach those' cause in reality the areas they 'should not be' they cannot reach without your help anyway and I have a rule if you cannot get up on it or down from it by yourself you need to grow some more before you can use that area ... but I only ever have one infant and the rest are all over 18 months and competent at climbing and so forth so I am comfortable with allowing them to just 'go' ... I have 18 months old who use the entire climbers competently and can climb the monkey bars and so forth because they have been spending every day for 6 months building their muscles and coordination and were determined to do it and I have 3 year olds who are content to play in the sand because well they are not interested in those 'risky' climbing things ~ all kids are different for sure.