We almost always dive from shore. We do not need a boat, to see and dive at the nicest areas. At La Palma we do not have a lot of currents and we can dive throughout the year. Sometimes (and that is mostly in the South of the island) we have to take the full and new moon into account.
The visibility is so average around 20 meters, so sometimes a bit better and sometimes a bit less. And it can also change a lot during a diving day, due to the tides. We also always try to find a dive site where the chance of good visibility is best. If we already know in advance that the visibility of a particular spot is not too good, we will move to the other dive site.