Altenau
Take a walk up Holtenau straße, away from town, to get to Holtenau, a lovely area of town that used to be independent of Kiel, but which has now been encompassed by the city. it is a fairly long walk, and you can go via the Höchbrücke or the passenger ferry, both of which afford great views of the canals, and the huge ships that come through.
There's a wonderful lighthouse in Holtenau, as well as a wonderful restaurant, and several Tall ships are usually anchored in the harbour there. It is possible to take a bus there, but i couldn't tell you the number, as i walked everywhere.

take a running leap off the jetty into the water
Ahoy!
Sculpture in the Schoss Garten
a cargo ship on the Kiel canal