STCW BST under 200 tons any good?

I have a chance to take a BST class in my neighborhood which is for vessels under 200 tons. I’m interested in perhaps working on a research vessel or ferry including international voyages, would this STCW cert. be any good? Or should I travel to take the five day BST instead? I’m considering the local one because it’s close and convenient. I’ve only got an OS mmc.