I've been on two cruises that docked in Bilbao, and on both occasions there was a shuttle bus into the city centre. The port is about 10km from the city and the shuttle bus dropped us in Plaza Moyua, the main square. This area is the shopping district with a huge variety of shops, department stores and restaurants. From Plaza Moyua you can walk, or get a taxi to the Guggenheim museum situated in Abandoibarra overlooking the river. The museum is open from 10-8, closed on Mondays except for July/Aug and the entrance fee is about 10 Euro per person, over 65's 7 Euro, child under 12 free. Not sure how this compares with the cost of the ship's excursion and whether the shuttle bus to the city will be free of charge. I hope Oceana isn't scheduled to dock on a Monday! We thought the visit to the Guggenheim was excellent and the architecture of the building is amazing. If you turn right when leaving the museum from the front entrance and continue walking along Abandoibarra you will find a very modern shopping mall and a lovely park with sculptures. You may be able to walk alongside the river, but there was a lot of construction work in that area when I was last there. A word of warning; an American couple from the ship had their bag and watches snatched while their taxi was waiting at traffic lights. This soured their opinion of Bilbao, although we didn't have any problems and thought it was a lovely city. Much as in any large busy city, be vigilant and watch your bags and wallets. Happy cruising - Jan .
Further to my previous comments I should have also advised you to visit the Tourist Information Office, close to the Guggenheim and pick up a map of the city. We also got a very useful free guide book from there called 'Essential Bilbao Bizkaia', it contains all the information you need to get the best from the city. Jan.