According to Russ Rowlett: Under a 1973 treaty, this lighthouse stands in "shared waters," where Argentina and Uruguay share jurisdiction. The treaty provides that both countries may build and maintain navigational aids in shared waters. Argentina maintains navigational aids in this area, very close to the coast of Uruguay, because the shipping channel leads to Argentine ports on the Río Uruguay and Río Paraná. Uruguay owns the economic rights to the seabed under the lighthouse, and if future sedimentation should bring the shoal to the surface the resulting island would be Uruguayan territory.