Keyper at Sea is an expansion of the game Keyper which includes 2 versions: the Shallow Water game and the Deep Water game, plus solo mode games for both Keyper and Keyper at Sea - Shallow Water by Dávid Turczi.
Keyper at Sea introduces a 'folding' sea board, replacing the country board in the Shallow Water game, but as an additional board in the Deep Water game. The sea board contains additional water spaces and introduces the fish market field.
In addition there is a fish market board, fishing boats, fish fairs, store tiles, sea creatures and treasures.
In the Deep Water game, players complete the seasons on different turns. The first player to complete a season gains a store tile and then plays through that season for a second time. This is an unusual concept which can provide new and interesting game challenges. Keyper at Sea presents players with more scoring opportunities than in the base game of Keyper and players are likely to be able to score achieve higher scores.
—description from the publisher