There are Metro stations- down the stairs... There are busses- street corner signs. But what does an RER stop look like? Underground too? RER looks very useful for us near the Eiffel Tower. Is Batobus the one you can hop on & off for 1 ticket?
I did an RER search & didn't find info I needed.
Thanks

Yes, exactly. The RER is usually found beneath metro stations so you enter the same way. They are underground and will have a sign on the street directing you. Not sure what batobus is.

Regarding Batobus (Seine shuttle)check this out www.batobus.com

Or maybe you are asking about www.paris-opentour.com

If you look at any Metro map of Paris, it will also show the RER lines.
Some of the RER stations are co-located with Metro stations; others are not.
Only RER line C goes near the Eifel Tower. It originates in Paris at Gare d'Austerlitz, runs along the left bank of the Seine, and divides after it leaves Champs de Mars and heads out of town with a few more stops.
At the primary interface stops, such as Invalides, it is a long walk from the Metro platform to the RER.
I never found the RER very useful for getting around Paris. It is great for going to Versailles.

Also, the Metro signs hovering above the entrance are not a consistent 'design'. Most are green or red rectangles with white lettering (METRO); there are a few that are a yellow circled M; a few that are the art nouveau design (green "vines&quot reading METROPOLITAIN.

The RER signs are black or blue and white, with a circled R.

For a sense of the transportation system within Paris, go to: http://www.paris.org/Metro/

The RER tracks are beneath the Metro lines; some are above ground. We used it quite a bit in April because we were near the d'Orsay and there was no metro stop there, just the RER. During the mid day and nights, it tends to be more deserted than the Metro; there were three of us and it still felt a bit odd; you need to pay attention to where you are going and what the electric signs tell you; it is not quite as easy to figure out as the Metro. I wouldn't do it alone at night. And it is more a train car (upstairs and lower level) than the Metro. We used the Paris Visite pass which was good for all three (bus, Metro and RER). The batobus is a water taxi boat; you pay from the point of entry to the point of departure. It is not included in the Paris Visite pass. It is a fun way to get from one water edge site to the next one you want. Unlike the tour boats, there is no dialogue.

Palette, there is a dialogue on the tour boats? I thought there was only a monologue

I stand corrected.