I'm not fishing in my shakespearian costume..one does not use placid..... Lest he be rent asunder... Calm is good for us peasants
"The lake is placid" -- 60,900 hits
"The lake is serene" -- 284,000
"The lake is calm" -- 763,000
"The lake is quiet" -- 8,930,000
An experienced fisher would say "I am fishing BECAUSE the lake is not placid." A little chop on the water makes for good fishing
An experienced native English speaker would NEVER say that a lake is placid unless he wants to sound very very silly.
And if he wanted to sound even sillier, he would call himself an experienced native English speaker.
This is a good example of a sentence in which "even though" is better. It is more like "despite the fact that" than "although."
On further thought, I see a difference. The Duo translation with "although" implies that maybe this was not such a good idea, whereas with 'even though" the speaker is displaying bravado.
Calm is the word most native English speakers would use in 2020.
Usually placid is a word we apply to people not nature. A lake would be calm or still, not placid.
Lake Placid is a ski resort in New York and has hosted the Winter Olympics a couple of times but that's the only lake that I would ever consider describing as placid, lol.
The lake is not calm, in my book.