A vessel, such as an insulated container, for liquids having a lower portion sealed with an upper portion, such upper portion having a drinking reservoir for holding liquid which is pumped from the lower portion through a dispensing passage, such as a liquid dispensing tube, by a pump mechanism coupled with the upper portion. The pump mechanism is ergonomically operable by way of depressing a feature of the pump mechanism, e.g., by a single finger of the same hand holding the vessel. The upper portion, coupled with the pump mechanism, is redisposable on the lower portion, transposable in relation to any other lower portion, and retrofittable in relation to any other interfaceable pre-existing containers. The pump mechanism is optionally provided with a button or soft membrane. The components of the vessel are easily disassembled and reassembled for facilitating cleaning thereof.