The bay is defined on the southern end by Cape Seal at the terminus of the Robberg (Afrikaans for Seal Mountain) Peninsula, separating the bay from the open Indian Ocean. It is one of the southern cape coast's typical "J-shaped" bays, which is formed by wave action eroding the shales of the Bokkeveld Group between the weather-resistant headlands composed of the Table Mountain Group, both of the Cape Supergroup geological sequence of rocks. To the north, the Tsitsikamma and Langkloof Mountains keeps the moisture on the southern slopes of the mountains and prevent the temperature extremes of the interior reaching the bay.