The straight-line (air) distance between Marsala, Sicily (Italy) and Hammam Rezeze (Hammam Rghis), Tunisia is approximately:
By sea, the crossing from Marsala to the Tunisian coast (near Kelibia) is ~80 nm (150 km), but Hammam Rezeze is inland southeast of Tunis, so the total route is longer. No direct ferry; travel via Tunis (flight/ferry + road) or Palermo–Tunis flight + transfer.