Yes. There are sightseeing boats which do river tours all year long.
how long wil it take to sail from RSA to Odessa
Trick question. You can't sail a steamship.
There is no set time it would take. Also, the time would greatly depend on the wind.
It would depend on what speed you were travelling at.
11 days
100 years
2 hours
5 months
about 5 to 6 days
it takes 5 hours
90 days