I will correct solohobo one last time... The last water taxi (not ferry, although there is one) leaves Almirante at 6:30 not 3:30-4. Why would they stop running mid afternoon?? Anyway, the direct bus leaves San Jose at 10 in the morning and only goes to Changuinola. You are at risk of missing the last water taxi if the ride is slow. If you choose this option, leave the bus at the border and grab a taxi to Almirante. I got a collectivo a couple of weeks ago for 5 dollars. There are a couple of direct buses from panama city but you want the night one which leaves at 8. If you choose this option, you can easily take a bus to David and then a bus to Almirante if the direct is sold out. Your best option for time and money is the first bus from San Jose at 6 and then taxi from the border to Almirante. If you get a super cheap flight to Panama City, do that bus dress very warm for the bus. They like their AC freezing.