pre paid sim advice please
 

After having researched the various cards I am now confused by the rates
which seem to vary greatly. Any particular suggestions please for phoning the UK
from Puerto Rico mostly but also Antigua and the USA.
Thanks very much

Your best bet is to get a calling card in each of the countries you'll visit. Just make sure that they calling card you get doesn't have a lot of extra fees and conditions.

Thanks for the tip and it'll probably be the cheapest option too.
However not certain if I'll have the time or the chance as other than
Puerto Rico these are only one/two day stops each time.
Have been looking at Geosim ....

One problem you have with the US & PR is that most prepaid SIMs do not have good international rates. It may be best to combine a prepaid SIM with either a callback service or a low-cost calling card. Antigua is a separate problem. I'm not sure how to advise you there.