The funny thing is, the Germans called their sub tenders "milk cows" (Milchkühe*)...
Granted, they were (oversized) subs, but still.
(*Yannow, that Milchkuh [singular of Milchkühe] resupply sub in Arpeggio).
-- Edit: Turns out 「潜母」 is a submarine aircraft carrier (SSV) instead, like Shioi. Submarine tender would be 「潜母艦」. Bah. Kanji abbreviations can be kinda confusing ("submarine mother" vs "submarine mothership")