Humberside Police are searching for a 13-year-old boy who goes missing after swimming in the sea off Hornsea. The incident takes place on Tuesday evening near the South Promenade area, according to police statements cited by multiple outlets. Emergency services are called at around 6pm, with reports describing the boy as having entered the water and not being located afterward. Outlets describe the response as a search and rescue operation involving police and other emergency services. The search focuses on the shoreline and surrounding sea area off the North Sea coast near Hornsea. Authorities ask for information that could help locate the missing boy, though specific appeals and updates are not detailed in the provided excerpts. The circumstances of how the boy went missing and the current status of the search are not confirmed in the summaries, but all sources agree that Humberside Police lead the efforts to find him following the swimming incident on Tuesday evening.