Best swell direction: South, southwest
Best wind direction: Anything north of due east or west. South winds blow it out easily.
Best tide: Higher tides, although it will break at all tides. Exposed reef at low tide.
How to get there from Reykjavik: Take route 41 south towards Keflavik. Make a left turn at Grindavik sign (also Blue Lagoon sign). Drive along road past Blue Lagoon into Grindavik. Go straight through town, over two speed bumps. After second speed bump near police station, look for road called Vesturbraut near a church and red house. Make a right onto Vesturbraut and follow road straight. It will turn into a dirt road and go through a farm. At the intersection, go straight. You will see a large antenna and a low seawall/reef area. The main break is in front of the reef area- there is a slight bluff where you will be looking at the break.
Notes: Grindavik is my personal favorite break in Iceland. It is usually powerful and breaks faster than Sandvik. On a solid swell and north wind, it can be very hollow and break hard on the reef. The break will shift depending on the tide; at low tide it can be very shallow to dry reef depending on the swell size. There is a slight channel on the left side of the break. There is also a right that breaks on the northern (right) side of the main break that has been ridden.