Just ordered a Echomap 93 SV chirp. I'm just trying to get everything ready when it gets here. I have a question about card size for the unit. I plan on doing a lot of recording so I want to get the best bang for the buck. As far as do's and don'ts and card sizes, is there any suggestions out there? I was thinking at least a 64Gb, but don't want it to be a waste of time if the machine will not read it. Any help will be greatly appreciated.