One of the key features of Breakwaters is the ability to bend water to your will (well, sort of). You gain the ability to push water away to discover the treasures buried under its surface. Gaining this ability is no simple task, however, and will require a bit of work. Here is how to push water away in Breakwaters.
You may have noticed the yellow crystals scattered across the island. If you look closely, you will see that these crystals repel water. You will be taking advantage of that ability here in a moment. Before that, you need to build a Builder’s Bench. This will cost you eight seagrass and 10 tree branches. You can then build the workbench from your inventory screen.
After you place the workbench down, it is time to start hunting for yellow crystals. When you destroy a yellow crystal, you get two different materials; yellow crystals and yellow shards. For now, you will be using the yellow shards. You will also need to find some empty bottles. Those are found by combing the beach and can occasionally be dropped by enemies. Once you have eight yellow shards and one bottle you will be ready to craft.
Head back to the workbench and select the tools tab. One of the first items you can craft on the list is a Refined Yellow Crystal. Craft the item and equip it. Throw it at the water and wherever it lands, the water will rush away from it. You can now search under the sea.