Adam Clarke on Numbers 33:10

Encamped by the Red Sea - It is difficult to assign the place of this encampment, as the Israelites were now on their way to Mount Sinai, which lay considerably to the east of Elim, and consequently farther from the sea than the former station. It might be called by the Red Sea, as the Israelites had it, as the principal object, still in view. This station however is mentioned nowhere else. By the Red Sea we are not to understand a sea, the waters of which are red, or the sand red, or any thing else about or in it red; for nothing of this kind appears. It is called in Hebrew ים סוף yam suph, which signifies the weedy sea. The Septuagint rendered the original by θαλασσα εραθρα, and the Vulgate after it by mare rubrum, and the European versions followed these, and, in opposition to etymology and reason, translated it the Red Sea. See the note on Exo 10:19.

Stat. 7.