Being 36 years of age I dare say I could be considered an adult, I am incredibly scared of water, this along with the fact that I can not swim myself would mean that I would mot certainly not jump in.. For me the risk would have been great and rather than allowing rescuers to focus on the Children I would have simply been an additional burden.

Its the parents responsibility for knowing where their kids are and to ensure they are safe, if a 8 year old is playing on train tracks, its inappropriate to be critical of the police for not jumping in front of a train to save the child... Where are the parents !!!

PCSO's can depending upon where they work, carry a great deal of kit including stab proof vests which I dare say can not be easy to swim in... everyone makes it sound as if they sat there, watching and did absolutely nothing at all to assist or resolve the matter which is not the case.
The PCSO main role is to communicate with the public. Many community's do not trust the police and this is why the PCSO has limited powers to reassure people that they are not going to get in trouble or involved when reporting crime.