Kaiboukans are basically frigates. They were originally intended for patrol and fishery protection duties, hence the name (coastal defense ship). Of course, due to the exigencies of WWII, they are also pressed into the convoy escort role, and later models like to Etorofu-class are designed with higher emphasis on ASW (read: depth-charge whoring. Like, really, really spamming them to a ridiculous degree).
Closest USN equivalent would be PF, patrol frigate. It's not perfect, and the sole PF class (the Tacoma-class, itself derived from British frigates) in the USN has a vastly different overall design compared to the kaiboukans (the Tacoma is bigger, for one), but they fulfilled similar roles anyway. The USN also has DEs, destroyer escorts (Sammy is one), which are designed for a similar role ("convoy escorts"), but these are scaled down destroyers they can fulfill the role of a destroyer in a pinch (like what Sammy had aptly demonstrated) because they actually have destroyer guns and torpedoes.
(The torpedo distinction is even more important with regard to IJN combat doctrine. Generally, all IJN destroyers are expected to carry torpedoes. No torpedo = can't even qualify to be called a destroyer.)
Really, some people on wikia or reddit say PFs are inaccurate representations (because kaiboukans are borderline corvette-sized compared to American and British frigates), but really, calling them DEs is way, way worse and give people the false impression that they are destroyers. PF is the least of evils.
PF was what ONI initially classified the kaiboukans as anyway. The proper post-war classification is "escort vessel" or "escort ship", but that's a very vague term that doesn't give you any idea on how big the ship is or what armaments it carries (and can be easily confused with JMSDF destroyers, which are literally named "escort ships"/goeikan for political reasons).
TL;DR: PF is the closest hull code you're gonna get for kaiboukans unless you want to come up with something like E or EE for escort, or dig out coast guard hull code desginations which are likely going to be anachronistic.
Demundo said:
Wasn't Sam a DE?
seikenshin said:
DE isn't terminology used in the game in Japanese, they're Kaibokan. DE is a USN term.
Sam is a DE, but the closest IJN equivalent for the John C. Butler class would be "destroyer", which is why the game treats her as one.
Kaiboukans are way different (and don't have torps, an important distinction for the IJN and for Kancolle itself).
Confusion arose because some people threw around DE has a hull code for kaiboukans just because they were pressed into a similar role (convoy escort), never mind the huge discrepancy in ship size, armament, and design (including original design intent).