The movie consists of two separated stories that are bound by the theme about the summer seaside vacation as well as by the character of the plump teenager Pipsi.
The first segment is named The Dolphin, starring mostly children led by the witty plump teenager Pipsi (Petar Peychev).
The kids are obsessed by the story about a mysterious dolphin insinuated by a local fisherman and playboy who tries to tie affair with the elder sister of one of them.
The second segment is named The Amateur Photographer, starring one of the leading Bulgarian comic actors, Georgi Partsalev, in the role of uncle Mancho, an aging man who flirts with a young female colleague during a pseudo business trip at the seaside.
As usual for the films written by Mormarevi Brothers, With Children at the Seaside obtained wide popularity and became one of the classic Bulgarian comedies from the 1970s.