If you are building an RGB ring array over a vessel, this is the part most people start with. The 24-LED NeoPixel ring is 65.5 mm outer diameter, 52.3 mm inner, 3.2 mm thick and 6.5 g. It runs on 5 V, draws roughly 18 mA per LED at full constant current, and chains from a single data pin, so several rings stacked at different heights still need only one output.
The listed price is $16.95, dropping to $15.26 at ten units and $13.56 at a hundred. The 12-LED version is $8.95 if you want a tighter inner ring.
The important limitation is stated plainly: "It cannot be used with a Linux-based microcomputer or interpreted microcontroller". The protocol is timing-critical, so plan on an AVR, RP2040 or similar running at 8 MHz or better, not a Raspberry Pi driving pixels directly from Python.