The LIMNOS Water Sampler is an approved and uncomplicated instrument to take water samples up to 30 m depth. It consists of the holder device to hold two exchangeable 1000 ml glass bottles as sampling vessels. The LIMNOS Water Sampler is attached to a wire and lowered into the water in closed condition in order to prevent sample contamination by surface water. An ingeniously simple technique is used to keep the sampler closed during descent: Two silicone hoses are fixed in bent position. The sampler is activated by a messenger upon reaching the desired water depth. When the messenger hits the anvil, the silicone hoses spring up allowing water to ingress and air to drain the bottle. For transport and investigation of the samples, the glass bottles are simply unscrewed from the holder and closed with a lid. This avoids falsification of the sample by pouring it from one vessel to another.