When it comes to the oceans, grandiosity is the rule. In scale, and in their importance to us, the oceans are huge — they cover two-thirds of the world’s surface and contain 90 percent of the planet’s habitable space. Three billion people rely on them as a primary source of protein, and the rest of us rely on them for, well, a lot of other stuff — including our medicine, leisure, livelihood, transportation, culture, climate, cuisine, just to name a few. I mean, we call Earth the Blue Marble for a reason.

But for most of us, the sea is something considerably smaller: a sandy beach, a rocky coast, a tug on a line, a clam pried up from dark mud, sunblock, sunburn, salt in the eyes, cold spray, warm waves. Maybe the seaside is a place where you were innocent once (splashing in the wavelets, building a sandcastle). Maybe it is the first place you encountered death (the seal’s body rolling slackly at the edge of the surf).

So when it comes to the challenges facing our oceans, let’s make it personal. This month we’re bringing you the stories of 15 people who get down in the waves (literal and figurative) on the reg. From fisherman to surfer, activist to scientist, all 15 of our ocean heroes have an intimate knowledge of the sea and the massive problems facing it. Let’s see what they can teach the rest of us. Jump in.