Thank you Terry for your advice.
Isn't it funny how many people ask, "Don't you get bored when you're swimming lap after lap?" I find I have some much to think about and concentrate on I just wish I wasn't time restricted so much! And the TT is certainly going to add to these thoughts.
It's interesting reading your posts on pool practices using your TT and the insight you attain through its use - thanks again for the advice and for making swimming, for many people, not only a fulfilling exercise for the body but also for the mind.