In June of last year, Larry Connor was among those transfixed by the news of OceanGate’s Titan, the submersible that imploded while descending to the wreck of the Titanic, killing all five people aboard. But unlike most viewers, the Ohio billionaire was moved to take the unlikeliest of actions: Having already journeyed into the Mariana Trench, the world’s deepest location, Connor decided to commission his own submersible and visit the remains of the famed ship himself. As he explained to The New York Times in May, “I’m concerned that people associate diving subs, especially new or different subs, with danger or tragedy.” (Connor has since stopped granting interviews on the subject.) “We’re not thrill-seekers. We’re not big risk-takers,” he added. Connor’s $20 million, two-person sub, the 4000/2 Abyssal Explorer, is being constructed by Florida-based Triton Submarines, which currently has five machines in production, including two for private owners and another slated to become a cruise-ship attraction. A year ago, in the..