Every town or village in portugal no matter how small has its own flag this usually consists of symbols or pictures depicting something about the place against a quartered background.
The flag is flown over municipal buildings such as the Ferguesia, which I believe is a bit like our Town or Civic Hall, and there is usually a standard for carrying at ceremonial occassions.
Santa Luzia is no exception.
This is the flag which is flown on buildings. As Santa Luzia is essentialy a fishing village the flag depicts a fishing boat with a fishtrap which is self explanatory and an alcatruz. An alcatruz was origionaly a pot for holding wine or water usally made from terracotta. They are used to capture octopus now and tend to be generally made from black plastic. Interestingly the Alcatruz points back to the Moorish influence as they were first used as the pots on the irrigation water wheels the arabs famously introduced to Portugal (a spledid example of which can be seen in Tomar in central Portugal) and their very name is a derivative of the arabic 'Al-Kadush' meaning 'of irrigation'.
This is the standard which is carried on ceremonial occasions.
I have never seen either the flag or standard in use but you can be sure on future visits I will be keeping an eye open for them. I feel sure the standard will have been somwhere in the procession at the festival but if it was I am afraid it completely passed over me!!