Why Atlantic-built sloops served worldwide

Were Bittern-class sloops built specifically for the Atlantic?

They were ocean-going Royal Navy sloops built to withstand Atlantic and North Sea conditions, which also made them suitable for the Indian and Pacific oceans.

The Atlantic was a demanding design standard rather than a single operational assignment. A sloop able to survive that sea state could also serve across the Indian Ocean and Pacific, fitting the Royal Navy's global commitments. Surface similarities could still conceal structural differences in British carrier design.