sin of crossing sea - Samudrolanghana

 Samudrolanghana or Sagarollanghana

kala pani

a person can wipe away this offense in three years by eating little at every fourth meal time; bathing at dawn, noon and dusk; standing during the day; and seated during the night

https://en.wikipedia.org/wiki/Kala_pani_(taboo)

in the bellow link it mentioned that it is for all 3 upper casts. 

https://www.hinduismtoday.com/magazine/july-august-september-2008/2008-07-crossing-the-ocean/