I was only able to fish for two days but this is what I learned, in case someone who is interested stumbles across this topic. From shore you can catch grouper, barracuda, and small gts up to around 10 kgs. If you want anything bigger you have to go on a boat. Also there are very few places (compared to the entire perimeter of the islands) that are suitable to fish since most of the shoreline is made up of boulder walls to protect against storms. you are better off taking a ferry to one of the smaller islands around Penghu and trying your luck there.
