Turbo Tunnel is a shallow rocky canyon near Grande Island where divers pass through a narrow crack between rock faces rather than following an open reef line. The route is short but memorable: you work into the swell, time the surge, and then glide through the slot while fish hold position around the sponge- and urchin-covered walls. The site is not deep, but control matters because the fun of the dive comes from moving with the water without brushing the rock or sea urchins. It is a strong fit for divers who want an energetic Goa swim-through with easy depth and a more topographic feel than the usual flat training reef.