SeaDronesSee

From the catalogue. Listed by one researcher from one source page.

• id: seadronessee
• kind: aerial
• robot or device: UAV over open water (class: aerial)
• how collected: UAV capture with manual annotation
• size as stated: over 54,000 frames, 400,000 instances
• hours: not stated | hours only claimed: none | episodes: not stated
• year: 2021
• organisation: University of Tuebingen
• licence: not stated (class: not stated)
• access: open (class: open)
• link (paper): https://arxiv.org/abs/2105.01922

Confirm the licence at the link before relying on it.