出没 しゅつぼつ
shutsubotsu

Noun
Suru Verb

1. making frequent appearances; appearing often; appearing and disappearing

Intransitive
かつてこの海域 かいいきには海賊 かいぞくがよく出没 しゅつぼつしていた。
katsute kono kaiikiniwa kaizokuga yoku shutsubotsu shite ita.
Pirates once appeared frequently in this area of the sea.