For sale is a Sea & Sea YS-30 TTL/Duo underwater strobe in its original box, including the original paperwork and diffuser.

The YS-30 TTL/Duo is a compact underwater strobe that was marketed as a small, lightweight unit especially suited to macro photography, fill flash, and other situations where a larger strobe would be cumbersome. Backscatter’s archived product page describes it as one of the smaller and lighter strobes and notes its usefulness for macro work and confined environments.

A key feature of the TTL/Duo version is its dual capability: it can operate in corded TTL mode with compatible Sea & Sea systems, and it also supports cordless TTL slave operation, allowing it to fire in TTL mode from a main TTL strobe without a sync cord in the appropriate setup. Backscatter states that the built-in Duo circuit works with both 5-pin and 4-pin Sea & Sea cameras and housings, and the manual includes a dedicated section on cordless TTL photography. 

Published specs from Backscatter’s archived listing include a guide number of 20 (ISO 100, land), approximately 80° x 55° beam angle, compatibility with 2 AA batteries, and a 2-second full-power recycle time with Ni-MH batteries. Backscatter also lists 300 flashes at full power with Ni-MH batteries and a 60m / 200 ft depth rating.

Please review all photos carefully for cosmetic condition and included accessories. Because this is a vintage underwater strobe, buyers should verify compatibility with their particular housing, sync system, and camera setup before purchase.