Talk:Summer 2019 Event/@comment-171.246.101.189-20190907021806/@comment-155.4.63.175-20190907102717

You can sub-cheese the map, which will limit your bucket use to around one per sortie.

Depending on how many subs and docks you have available, you can even run the map multiple times without spending any buckets at all. I have 9 subs + 4 docks and my bucket count actually increased while I was farming for Yu-chan (~30 sorties per day, on hard).

If you have Richelieu the boss can be S-ranked quite consistently. Only thing you need to be careful with is AACI, as de-planing the boss will make her ignore your submarine.