The charters and others that fish a lot have a network of other fishermen they talk to get current info as to where the current bite is.Myself,and others keep a journal as to where they have fished at certain times of the year and caught fish.Then go to those areas related to where they have caught past seasons.
You can look at all the fishing posts and sometimes find a current location where people are catching.Capt Sam posted he recently headed east out of Huron to catch his fish.Most posts don't tell where they fished though.
If your transducer is placed correctly,you can mark fish moving at cruising speed.So that would greatly help finding fish in open water.Others like to chase the pack of boats they see.Sometimes that works,but can turn off what was once a good bite.Try and avoid the middle of pack and troll on the edges.