That claim of it being from "πάλιν οὐρεῖν" (palin ourein, iterum meiere)
is pure jest in Martial's poem.
Palinurus doesn't appear in Homer.
"From the high point on Capo Palinuro, one gets a superb view of the
coastline of Il Cilento. Toward the north, one sees the town of Palinuro
tucked into the "elbow" of the "arm" formed by the cape, and then the
long stretches of sandy beaches that lie between Palinuro and the
mountains that drop down to the sea. Toward the south one sees the high
cliffs that border the sea between Capo Palinuro and Marina di Camerota.
Viewing that terrain, one can imagine the sighs of relief expelled by
the ancient sailors who had safely passed that stretch of cliffs and the
cape to pull into the well protected landing place at the town of Palinuro."
http://www.sersale.org/mancuso/cilenvis.html
No mention of swampy land in the area (nor of stakes either).
Vergil's account of Palinurus seems modelled on that of Menelaus'
helmsman Phrontes in Homer's Odyssey book 3.
Ed