Common Backswimmer unusual behaviour

The two photographs above were taken in my pond on 09/03/14, and show the Common Backswimmer Notonecta glauca, which is sometimes known as the Greater Water Boatman.  The top photograph shows the insect crawling out of the water onto the side of a marginal basket.  It would then seem to struggle up the basket for a short way before falling back into the pond again. It attempted this several times before giving up. I have never witnessed this behaviour before and would love to know what was going on.

I know the life cycle is egg - nymph - adult. The nymph looks like the adult, but the wings are not fully formed, and as it grows bigger it has to shed its skin several times. I just wonder if this is a nymph and this was the process it was going through?