"Water Lot of Fun II" by Ruinae Retroque Rursus, a custom level for Manic Miners porting a custom LEGO Rock Raiders level of the same name, itself based on the level Water Lot Of Fun from LEGO Rock Raiders.
Objectives: Collect 15 crystals
Water Lot of Fun II
I hope you don't mind water, Cadet! An underground river has burst its banks and devastated our Mining HQ! All that is left is the Docks and the Support Station. There are still valuable Energy Crystals to be found and we must continue our mining operation.
Port of the RRU map: https://www.rockraidersunited.com/topic/8623-water-lot-of-fun-ii/ This level is waaay less cancerous than the original Water Lot of Fun which I found very garbage and always exploited to win since it was so bad (you can collect 15 crystals on your side of the river to begin with). This is more of a puzzle of how to use your highly limited crystals - yes it is possible, don't @ me saying it isn't. Look harder.