Thanks For the replies.
Stuart since i posted this i have purchased a swimovate watch and also a tempo trainer and i found both of these to be terrific.
I have complete another 80 lap swim and also a 100 lap swim and it was good to be able to quickly stop and start it with a button push after each 20 laps to later go back over and look at the splits later.
This week the summer has come to an end and its getting too cold for me for ocean swims so its going to be back to the pool for drills and practice for the winter to get ready to enter my first competition swims next summer and cannot wait but have i got some work to do to increase my speed and make my style anything near TI swimming and hopefully i'll have fun trying and not get to frustrated.
30min/mile, now there's my challenge for the winter