As NCIS prepares its return to the 2026 TV schedule and is (hopefully) ready to resolve its huge cliffhanger, its cast is looking back at some of the other big mysteries of the series. Co-stars Brian Dietzen and Diona Reasonover recently did an interview with EP Scott Williams and finally got into the mystery surrounding Gibbs' boat. Leroy Jethro Gibbs enjoyed building boats, and while NCIS: Origins got into the reason behind that, Williams was a guest on Partners and Probies to discuss a question fans had for a long time. For years, Gibbs was building a boat in his basement. For those who were unaware, here's a picture: (Image credit: CBS)It's a beaut, but the hosts had to put Williams on the spot because it felt similar to building a ship in a bottle. Fans couldn't figure out how Gibbs would remove the boat from the basement after he built it, though the EP revealed they did cheekily address that in an episode a while back: When I first got there, I think they had taken it out once and they never explained it to anybody. But we think we explained it where he knocked out a wall and you know, was it right when Ziva came back, we worked out a thing where we had to have her escape, pulled it out, and he said something like, 'Well, how else would I get it out?'As revealed in Gibbs' final NCIS appearance (Mark Harmon will return in NCIS: Origins), the character broke a hole with a sledgehammer in his wall just large enough for a boat to fit through. The boat ultimately blew up, but we know that Gibbs escaped with his life and even recently returned off-camera to deal some vigilante justice to the killer of Director Vance. The answer to the boat mystery wasn't the most exciting explanation, but as Scott Williams pointed out, the mystery was never really the point of the boat storyline. The process of building a boat, and what it meant to Gibbs, was the real story, so Williams wasn't too worried about any explanation of how it would be removed: It was one of those cool mysteries where they were happy to just kind of go, does it matter? He's enjoying building it, and it's, you know, there was something very sort of zen about it. It was like, you know, getting it out of here doesn't matter. It's just the work I put into making it pretty down here. I like that.I also like that, and think it adds more depth to the already mysterious Gibbs. I do think it's weird he never had a better plan for removing the boat, however, especially for a guy who prides himself on following a strict set of rules. Do you think after he had to break a wall, he added "Never build a boat in a basement" to his list?With Mark Harmon showing up in NCIS: Origins, I do wonder if this means we'll also see him in a new episode of NCIS in the future. As previously mentioned, he helped Alden Parker break the law and bring Director Vance's killer to justice. There were suspicions that Parker and Gibbs were involved in the murder, but an investigation into the issue was never officially opened. Paramount+: from $8.99 a month/$89.99 a yearWatch old episodes of NCIS over on Paramount+. Between the Essential plan running $8.99 a month and the ad-free Premium option at $13.99 a month, there's plenty to choose from with Paramount+. But if you want to watch your favorite shows and movies, and save some money doing so, sign up for an annual plan.View DealWe'll see what's in store when NCIS returns to CBS on the fall schedule. In the meantime, fans can revisit past episodes with Gibbs over on Paramount+, and see him working on that boat from time to time.