Thanks for your comments, it seems there was a misunderstanding. The boat from Corralejo leaves at 5:30 and 7:30, from Playa Blanca at 4:30 and 6:30, perhaps you did not explain yourself well or the crew member did not understand you properly. In any case, the information on the schedules appears on the ship and in the port in several places, also when making the reservation, so we do not understand that they have lost an hour.
You also say that you found it confusing when they gave you the time, don't you think you should have checked it? It is very easy to blame a sailor who does not speak English well and does not have to, however you travel to another country and must worry that you are understood here.