Normally everyone who goes to the dry valleys goes by helecopter. The big reason is that all the ice usually melts around Mcmurdo by december and there is open water between the two. Since the B15a iceberg floated in and got stuck against the northern part of ross island, it’s been blocking any ice that breaks up from floating away. It also is blocking the large waves that roll in during storms, which normally aid the break up of the fast ice.
That being said. It is normal for a sea ice traverse early in the season along the fast ice to the base at Marble Point. It’s an emergency helecopter refueling station. It’s done with the large tire Delta vehicles. See the Winfly page for photo of a Delta