Well, while you are in Oban, which is known as the "gateway to the isles," it is more than worth going on all of the trips you can pack in, because it is just so beautiful up there! If you are staying in Oban, which I recommend, then it’s a short stroll to the docks, where you can find out about trips around the isles. Just a 10-minute boat trip from the pier, you can see the seal colony - which for children is magical (and adults alike). Further afield, you find the isle of Kerrera, where you can walk to your heart’s content and the scenery really is amazing (keep an eye out for the otters).
If you are interested in seeing the isles surrounding Oban, then pick up leaflets from the tourism office on the dock or the ferry terminal. They can help you as much as you need in there - great place.
The boats are well kitted out and fine for travelling these short distances. If, however, you do what we did and plan to spend a few romantic nights in Oban, then think again. Not that you can't have romantic nights - because YOU CAN! But not on the boats! We took a romantic sunset cruise (as advertised) with dinner aboard one of the boats in the luxury restaurant. Sounds great, doesn't it?! Well, the sun sets about two minutes after you get out of the harbour, and most islands have only one or two houses on them, so you will see no lights. Outside of the window, you will see BLACK. And nothing else. There is no view after dark. The restaurants on the boats are all okay - nicely set out, BUT the food is a bit bland. You are offered a range of meals from a menu and you tick which one you want and send the form back. Sure, you get the meal that you wanted and it is what they said, but it’s very "out of a carton" tasting.
On top of that, the boat seems to pick up a lot of swell even on calm nights, and so a lot of people were in and out of the toilet all night. For us, the peak of the evening was when the so-called entertainment came on and it was three men in silly costumes with bells and hurdy-gurdies singing in an inebriated fashion to some locals who were using the ferry to get back from one of the islands. Most people hid in the room downstairs and counted the minutes till we got back to port. AVOID THIS!