According to William of Apulia's The Deeds of Robert Guiscard, although his Norse roots would seem to suggest otherwise, until the invasion of Sicily, Guiscard had not participated in naval warfare.
Menurut Guglielmo dari Puglia Deeds of Robert Guiscard, meskipun akar Norse-nya tampaknya menunjukkan sebaliknya, hingga penyerangan Sisilia, Guiscard tidak ikut serta dalam peperangan laut.