Further to my last little input I have managed to get the code to compile and run on my MAYFLY with a MB7389 sonar by changing the #include <Sodaq_PcInt_Mod.h> to #include <Sodaq_PcInt_PCINT0.h> and
#include <SoftwareSerialMod.h> to #include <SoftwareSerial_PCINT12.h>
also a few lines down form there I changed
SoftwareSerialMod sonarSerial(11, -1); to SoftwareSerial sonarSerial(11, -1);
It all seems to be working fine after making these changes but wonder if I may be doing it wrong or potentially going to have problems.
Also the way I have it now seems to make the samples get taken every two minutes and I got the impression from the code it would be every minute, am I missing something??