By Aaron Dinkin and Allen Rabinovich.
Each puzzle in this round (well, except one) has the outline of a country in its header. The countries are:
Ohio (that's the "except one")
Reading clockwise around the lagoon from the left side, the initials of the countries spell out MCMURDO STATION.
On the map, the lagoon contains long and short boats. Interpreting a short boat as a Morse code dot and a long boat as a dash, reading clockwise spells out STEWIE GRIFFIN.
So the eighth agent is Stewie Griffin, and he is located in McMurdo Station, Antarctica.