Imagine I have a seastead, which is kind of like a tiny oil platform for one family,
and it uses submersible mixers with 8 foot propellers and lots of solar power to go like 
1 MPH all day long.

I live in Anguilla, in the Caribbean.  Looking at ocean current charts like
https://www.myfoxhurricane.com/rtofs_current_car.html
there are lots of eddie currents.  If we are only moving at 1 MPH relative to
the current we are in, then choosing what current we are in can make a big
difference in our progress toward some destination.

What sources predict eddies for the future?  How far is reliable?

Are there existing software packages or algorithms that work well given
existing forecasts for eddies?  Is there any open source software for this?

In practice we won't be going in a straight line, so we will cover more total 
distance.  But if most of the time the current is in our favor we might average
well over 1 MPH toward our destination.   How well do you think this can work 
in practice?

The eddies can not be going through land so it seems like we don't have to worry 
about a 2 MPH current pushing our 1 MPH seastead into land, right?  We should
always be able to motor away from land (ignoring wind for the moment, just
looking at currents).

Please estimate how long, using eddies, this 1 MPH seastead might take to do a
loop around the Caribbean Sea.   You can go clockwise or counterclockwise.

I have seen the eddie data for the Caribbean but I don't know anything about
other places like the South Pacific or Mediteranian.   Are there usable eddies
in other places we might want to visit someday with our seastead?  What about around
the Eastern coast of South America?