I d do the HOHO bus thing,,BUT,,IF you need a guide
don t just rely on one name ,,,double check with a few internet guides,,and local tourist board by just googling.Then ask for recommendations to check,,do NOT pay ahead of time.Remember if you go on own,,whether HOHO or guide..its up to YOU to get back to ship if TIME...
We took HOHO and had plenty of time to see what WE WANTED to see.Check ahead of time to find what interests YOU.It s easy to get on and off bus,even for 80 yr.old and bus lets you off right in front of main attractions ,,so very little walking.
Getting to the post rather late, but we did Oslo on our own. Bought a day pass for subway and buses and went everywhere. We had plenty of time. No need for tour if you are able to walk and navigate stairs of bus and subway. National Museum was closed - we were there on a Monday, closed Mondays but as there are two copies of The Scream in Oslo, we took subway to the Munsch Museum. Took subway then bus (maybe 15 min) to Vigeland as well. Everything pretty accessible on Subway line. And. we did this all in pouring rain!!! Ship docks a pier and it is a maybe ten min walk to city hall. Others on ship went to the islands surrounding pier with the same subway / train / bus ticket. We prefer subways to Ho Ho as lots of time, when they are full and you are waiting, they just pass you right by.