When the mother is jailed does the father then get custody?

That would be the logical action, yes.

Although it is the logical action, that does not necessarily mean the laws of each state are logical. The answer to this question is no, for parents in Florida who are not married.

If you are married, I believe it's different & the marriage makes both parents legal guardians. And so the father would already have custody, therefore no disputes. But I may be wrong on that. I'm not a lawyer, just someone with experience in this area. And it probably gets way more complicated if the child was from a previous marriage.

I'm sure each state has different laws on custody, so it could vary slightly state to state. I know though that if you dont have custody rights to begin with, meaning you did not marry the mother, then you still don't have rights when the mother goes to jail. I know because that happened to me. The mother had to verbally agree in front of two police officers to grant temporary custody to me. In my case, the police decided the mother was too drunk to make her own decisions, so they appealed to the Grandmother of the child on the mother's side since that's where the child stayed with the mother.

-- High School Teacher