Chitose

Info
Chitose (and her sister Chiyoda) can remodel five times and convert to light carrier at level 15. You can keep her as a seaplane tender (AV) and choose not to remodel her to carrier, as AV maintenance cost is low and Chitose A have an opening torpedo attack with type A sub installed which comes for free at lv12 upgrade.

Build
A common "by-product" from aircraft carrier formula

Sources and External Links
Japanese_aircraft_carrier_Chitose