Hydra taksih kalebet satunggal kulawarga saking rasi lintang Hercules, sesarengan kaliyan rasi lintang Hercules, Sagitta, Aquila, Lyra, Cygnus, Vulpecula, Sextans, Crater, Corvus, Ophiuchus, Serpens, Scutum, Centaurus, Lupus, Corona Australis, Ara, Triangulum Australe lan Crux. Rasi lintang Hydra ugi dipunkiteri déning rasi lintang sanèsipun kados ta rasi lintang Antlia, Cancer, Canis Minor, Centaurus, Corvus, Crater, Leo, Libra, Lupus, Monoceros, Puppis, Pyxis, Sextans lan Virgo.