Pt.II

“...although there is little evidence to support this, some historians argue that the maritime musical form can be traced as far back as Ancient Egypt...” [Reidler, see OP]

Wiki
“Etymology
The phenomenon of using songs or chants, in some form, to accompany sea labor preceded the emergence of the term "shanty" in the historical record of the mid-19th century.

Emergence
Singing or chanting has been done to accompany labor on seagoing vessels among various cultural groups at various times and in various places. A reference to what seems to be a sailor's hauling chant in The Complaynt of Scotland (1549) is a popularly cited example.

Work chants and "sing-outs"
There is a notable lack of historical references to anything like shanties, as they would come to be known, in the entirety of the 18th century. In the second half of the 18th century, English and French sailors were using simple chants to coordinate a few shipboard tasks that required unanimous effort.”


Where we're at:
Martial et al should suffice for a “maritime musical form” in general being a part of the military, business and artistic communities, including Hellenistic Egypt, since the first century AD, romanticism and all. Sheerin's notes & bibliography alone will do the trick, if you can get at it.

And it's still only 200AD.