Amphibious Units

[Takeo]

I'm at the point of adding Amphibious units to my personal mod and I can't remember the exact abilities they receive(besides attacking from the water). For some reason I had thought for years that the marine's att value was doubled when attacking from the water. Is this true? When I researched here at this site, I found that the marine would ignore walls and fortifications. Is this true, or do they ignore everything that would modify the defense value of the defending unit?

Thank You for any info you can give me!

 

[Jorsalfare]

I don't think they get higher attack strength when attacking from water, but I believe I have read somewhere that they don't suffer a penalty when attacking across a river. I have never noticed that they ignore fortifications in a city.