With accent marks:
Рыба́к рыбака́ ви́дит издалека́.
A fisherman sees a fisherman from afar.
Today we understand this proverb as "people with similar interests will always find a common language". In this sense, the closest English equivalent would be "birds of a feather flock together".
Although in the original version, the meaning of the proverb was much closer to the modern joke "a fisherman hates a fisherman from afar". Because in the full version, it sounded like this: "Рыбак рыбака видит издалека, потому и стороной обходит" (a fisherman sees a fisherman from afar, therefore he avoids him).
Other Russian proverbs
Eggs don't teach the chicken.
In a quiet whirlpool, demons live.
What goes around comes around.
A bad example is contagious.
A titmouse in hands is better than a crane in the sky.
Make a fool pray to God - he will break his forehead.
If I knew where I would fall, I would lay some straw there.
Do not chop the branch you sit on