This dataset contains measured underwater acoustic channel impulse responses (CIRs) collected during at-sea experiments spanning diverse geographic locations, environmental conditions, and system configurations. Each CIR captures how a transmitted acoustic signal is modified by the ocean environment as a function of propagation delay, and evolves over time to reflect the non-stationary nature of the underwater channel. The collection currently includes eight channel datasets, identified by color labels (Blue, Red, Yellow, Purple, Green, Black, Pink, Brown). These span locations including the North Atlantic, Singapore, Hawaii, Norway, Japan, the Mariana Trench, and the Pacific Ocean, with transmission ranges from tens of meters to thousands of kilometers, center frequencies from 75 Hz to 25 kHz, and receiver configurations ranging from single hydrophones to vertical, cross, and planar arrays. Each channel is stored as a compressed complex-baseband channel matrix in MATLAB format (.mat), accompanied by a phase vector that encodes the time-varying delay drift suppressed during compression. Full reconstruction instructions and ready-to-use toolboxes in MATLAB and Python are available at https://github.com/uwa-channels. This library is intended to support reproducible research and benchmarking in underwater acoustic communications, channel modeling, and signal processing. Researchers can apply the provided channels directly to signals of their choice using the companion software.