Battleship kills that do get counted
To make a long story short: cruisers and destroyers are always ships and thus safe. All other battleships are solars, with the following exceptions:
- mission 4: Battleship Unity near Manhattan (see below)
- mission 10: the four battleships in Sigma-13 (Fenrir, Jormungand, Geri, Loki)
- mission 11: Battleship Texas and Arizona in Alaska (but they are invulnerable)
- mission 11: Battleship Omaha in Zone 21
The following provisos apply: Battleship Unity stops taking damage when hitpoints are down to 1%, until the 'code red' sound file has finished playing. Chances of bagging this kill are slim but it is doable - if you have nothing else to do then start firing on the ship when you hear the 'code red' comm. The Texas and the Arizona stop taking damage when hitpoints are down to 10%, and they do not become fully vulnerable until Walker is within 1000 m and the cutscene kicks in. No chance here.
That leaves only the Sigma-13 ships and the Omaha ...
Here is a list with all possible battleship kills, including cruisers. In most cases there are timeouts of various sorts and so it is impossible to get all of them; exceptions are noted.
Mission 4
- Manhattan: 2 cruisers, BS Unity
- Benford: 3 cruisers
Mission 7
- Leeds: 1 cruiser (no timeout, but Tobias & friends interfere)
- Tau-29: 3 cruisers (no timeout, but do work quickly - cruisers are fragile)
Mission 9
- Tohoku: Destroyer KNF Hissatsu
Mission 10
- Sigma-13: four battleships, up to five? cruisers (4 main + 2 reserve)
- experimental shipyard: 3 cruisers (apparently no timeout until you destroy an experimental ship)
Mission 11
- Zone 21: Battleship Omaha, 3 cruisers (they like to do a Molly, so work quickly)