Edge to the Brink

From the edge of the Sea
At the brink of the Earth
A river flows backwards
On to the struggling boat
Rowing towards the Sea 
On it's desperate quest to
Leave the Earth forever,
Forgotten, murky, forlorn.
Neither the wind favours
Nor does the tide allow,
The oars row fatigued
Yet the boat remains just
Where it set out for voyage.
Would there be a freak gust;
Or a fated turn of the tide;
Or forever is it destined to 
Row in ennui yet only fail?