Make the brine - Bring the water and the salt to a boil, stirring to dissolve the salt. Take off of the heat and let the brine come to room temperature.
Prep cucumbers and garlic - Wash the cucumbers and trim the ends. Soak in a large bowl of cold water for at least 20 minutes (up to one hour). Peel and smash the garlic.
Pack the jar - Drain the cucumbers and add them to the jar. Drop in the garlic and the dill and pour in the brine, to cover. Add a fermentation weight to keep the cucumbers submerged during fermentation. Cover with the airlock (adding water as a seal, if that's the type of lock you're using.)
Ferment - Place the jar in a place that's out of direct sun and leave to ferment for at least two weeks. Check on the pickles from time to time. They're ready when they taste pleasantly sour. They will have lost their vivid green color, but they'll remain incredibly crunchy.