brand new to kayaks need help with reading tides and currents so i know when to go

[MADISON080906]

i just bought a yak i live near galveston tx i plan to use the yak in the bay and in a lake fead by bay my question is how do yakers know when time is right to go on water and how do you know when to head back trying to figure out what factors to look for so i dont end up like gilligans island and i dont want to have to fight a hard current to fish so are there specific times or factors experienced yakers know?