Re: How would 2 planet's tides react to each other?

If the mass of the ocean on each planet is not too big as 
compared to the mass of the planet, the presence of an 
ocean on the other planet does not make a big difference on 
a first approximation.
 
This is the case of Earth, where the ocean mass is less than 
one thousandth of the Earth's mass. Tides are caused by the 
gravitational attraction of the whole mass of the other body. 
If one body has an ocean very small as compared to 
its total mass, it won't make a big difference on the 
other body tides. 

If the ocean mass must be taken into consideration 
on a second, more accurate approximation, the tides 
may vary in height depending on how each planet is 
rotating. Tides may be higher when the oceans on each 
planet are facing each other, but this would be noticeable 
only if the ocean has a sizable mass as compared to 
that of the planet. 

Vladimir Escalante Ramirez