However I'd like to see Ceuta. Seems more appealing than Tanger. Would it be an option to take the ferry to Tanger, go to Tetouan by taxi, take another taxi to Ceuta and from there the ferry back to Algeciras?
I seem to recall that most ferries to Tanger go via Tarifa (you can take a shuttle bus from Algeciras). Personally, I would prefer to stick to two locatios, Tetouan and Ceuta. There are at least 10 ferries daily costing 60.