Bridging the channel of ocean between Berk and Outcast Island, the Straits are a crucial trade route in the Archipelago. The narrow route is flanked by towering cliffs of jagged rocks and sea stacks before flowing into the mouth of an estuary and eventually, the open ocean.
Dragons: Race to the Edge
Having had his operations disrupted by Hiccup yet again, Viggo Grimborn decides to strike back by capturing a Submaripper and chain it up in the Straits of Baldur, preventing any trade ships from reaching Berk. The trader Derrick and the others were most likely killed by the Submaripper during the events of "Dire Straits". Only Johann and his ship survived. Fortunately, Hiccup succeeded in freeing the Submaripper, allowing ships to again reach Berk unharmed.
The Dragon Riders later assembled in the Straits of Baldur anticipating that Ryker Grimborn would attack Outcast Island during the events "Shell Shocked, Part 1", only for him to strike at Berserker Island instead, after drawing the riders out of the Straits of Baldur.