Merino Jarpa Island lies wholly within this great estuary, while at its mouth lies a group of smaller islands, called Baker Islands, which separate it from Messier Channel. Baker Channel also receives the waters of the O'Higgins/San Martín Lake through the Pascua River.
Merino Jarpa Island is entirely within this large estuary, and nearby are a collection of smaller islands named Baker Islands that demarcate it from Messier Channel. The Baker Channel is connected to O'Higgins/San Martín Lake via the Pascua River.