I took a halfday-cruise from Fionnphort to Iona, Staffa and Lunga and may hioghly recommend it to everyone !
As soon as you arrive in Fionnport, check out carefully the time-tables of the various different ships taking you to Iona, Staffa and / or Lunga, they differ a lot when it comes to the time that you may spend on the islands of Staffa and / or Lunga / Tresnish-islands.
On my picture you may see the boat that took us to Staffa and Lunga. We had to step up 20 minutes to the cliffs in order to get to the nests of the cute puffins: They build holes under the grass , where they have their nests, so you should really take one of the cruises, that leaves you at least 2 hours on the island of Lunga.
For Staffa 1 hour might be enough , because Fingals cave is where you will dock, and there is not a lot to see on the island itself, except the basalt-rocks at the small stoney beach !
For the timetable of the ships - take a look on my link below !
Iona is another island and in Scotland, that means Caledonia MacBrayne. For 3.85 pounds you can get a round trip ticket from Fionnphort on Mull over to Iona. Everyone goes as a foot passenger on this little boat. The seas can get a little wild on the ride across the Sound of Iona but you are only on the boat for ten minutes or so. Get over early or late in the day before all the tour buses get here - which is around noon.
When visiting Iona you have to leave your car in Fionnphort at a large car-parking directely at the port. A small ferry takes you that short distance between Fionnphort in the Island of Mull and the island of Iona and it runs almost all day to and fro on a regular basis.
That ferry may take a few cars with it, BUT only the local people are allowed to do so, for all the other passengers it is not allowed to take any cars with them (it would also not make sense, because of the short distances on the island)
Hiking and cycling makes sense on the island of Iona !
The MV Loch Buie plies between Fionnphort on Mull and Iona. Only islanders are allowed to take their cars over; for other visitors there is a car park at Fionnphort.
The last crossing is about 6 pm; when the tourists are gone, the island becomes very quiet.
You get to Iona via a pedestrian ferry from Fionnport. You can't take your vehicle unless you live on the island. You can take bicycles though. Otherwise, the only way to get around Iona is to walk. It's a small island, it wouldn't take all that long to walk around it but the roads don't go a whole lot past the village itself.