Ty Sunderland was pacing, his head bent intently over his phone. It was 5:52 p.m., eight minutes before 500 guests were expected to board the Circle Line Sightseeing Cruises boat where he was hosting a party on June 18, and the sound system had yet to be tuned.

Mr. Sunderland, 32, a D.J. and event producer who lives in Brooklyn, had begun firing off text messages to an engineer. The issue at hand threatened a choppy start to “Gayflower: Spice Girls,” this year’s inaugural installment of his annual Gayflower boat parties, which began in 2018 and are named after the Mayflower ship that ferried the pilgrims from England to Plymouth, Mass., in 1620.

Since the parties’ inception, each one has been a tribute to a different pop music act through both music and dress. Revelers, who are mostly gay men, often show up in outfits inspired by the artist being celebrated. As a sound engineer finished tuning the boat’s speakers, Mr. Sunderland shared his hopes for how attendees would honor the ’90s-era British girl group known for such hits as “Wannabe” and “Spice Up Your Life,” which originally comprised five members: Scary, Sporty, Ginger, Baby and Posh Spice.

“I want to see groups of five. I want to see signs. I want to see little Gucci dresses,” he said, referring to the black frocks worn by Posh, the former nom-de-spice of Victoria Beckham (née Adams), whose career as a fashion designer succeeded her time as a Spice Girl. “She’s fashion,” added Mr. Sunderland, who had worked as a buying assistant at the department store Barneys New York before becoming a nightlife fixture. “I love fashion and she was always serving.”

Mr. Sunderland, who said he began wearing black and white because the shades made him more recognizable at clubs, had thought about wearing a short black dress that evening. But he instead opted for one of his black-and-white caps from Stampd, of which he owns close to 100, black-and-white Adidas track pants and a black Nike warm-up jacket over a Spice Girls T-shirt. The separates, he concluded, would be more appropriate for spinning tracks on the open water amid temperatures that hovered just above 60 degrees.

Dressing practically was less of a concern for party guests, who cruised around Manhattan after boarding the boat at Pier 83 on the Hudson River. Ivan Lizardi, 27, another Posh Spice fan, wore a little black dress he had bought at Zara. “Posh is my favorite because she does the least amount of work,” said Mr. Lizardi, who works for the streaming platform Paramount+. “She just sits there and looks pretty. So relatable!”

Sean Riordan, 30, who was in town from California for his bachelor party, wore an outfit just as recognizable to Spice Girls followers: a dress featuring the Union Jack flag, a style famously worn by Geri Horner (née Halliwell), or Ginger Spice. A fan of the group since childhood, Mr. Riordan, who works in hospital administration, said he “had Spice Girls bedsheets, and my first Barbie was Spice Girls Barbie, which my dad threw a fit about.”

Whether dressed like the Spice Girls or not, many attendees were drawn to the event by a sense of nostalgia and a desire to celebrate “girl power,” a rallying cry of the group. Tim Fitzgerald, 27, who wore a more weather appropriate ensemble of leather jacket, hoodie and trousers (all black), recalled the impact that “Spice World,” the 1997 film starring the five Girls, had on him as a child.

“I watched ‘Spice World’ with my best friend growing up until the VHS tape ran dry,” said Mr. Fitzgerald, who works in public relations at the fashion brand Coach.

Guests paid up to $55 to attend the four-hour cruise, much of which was set to tracks from the group’s three studio albums: “Spice,” “Spiceworld” and “Forever.” (The third was recorded without Ginger, who left in 1998 to pursue a solo career.) Halfway through, the dancer and drag queen Brie Bordeaux performed in a pink minidress that the performer described as a mix of “Baby Spice and Elle Woods.”

Peppered among the drag show and the Spice Girls songs were tracks by other musical artists celebrated at past installments of the party, including Lady Gaga and Britney Spears. Ms. Spears was the inspiration behind Mr. Sunderland’s first Gayflower event, in the summer of 2018. Called “It’s Britney, Boat,” that party, which he describes as “the flagship” of the series, has been restaged every year since.

Those who have not attended one of the boat parties may be familiar with them because of the 2021 event honoring Ms. Spears, when an incident involving an unruly partygoer unexpectedly spread across social media.

“There was a DEMON twink on Britney boat last night …” Mr. Sunderland wrote on Twitter the day after the party, using a term to describe gay men with thin, hairless bodies who are typically young. “Threw a drink at the dj equipment, wouldn’t get off the stage unless I stopped the music,” continued his tweet, which listed another alleged transgression not fit for publication.

Mr. Sunderland’s post prompted tweets from others; one included a fake announcement that the character would be featured in a new Netflix series, another called for a line of demon twink merchandise. (There are now crop tops featuring the phrase for sale on Etsy.) Earlier this month, the incident came up on an episode of “Ziwe,” the Showtime talk show. “It was my little contribution to the gay lexicon, we know what a demon twink is now,” Mr. Sunderland said, adding, “it made straight people aware of what I do.”

By the time of the Spice Girls voyage, though, the specter of the demon twink had mostly been exorcised from the festivities. Aside from a few intrepid revelers who mounted the life jacket containers as the ship returned to its original berth, most guests were well behaved.

While any future demonic presences may be impossible to predict, the fate of the boat-party series is far more certain, according to Mr. Sunderland, who is also the host of Ty Tea, a regular Sunday event on land at the club 3 Dollar Bill in Brooklyn. This year’s lineup features five more excursions, including “Gayflower: Bangerz,” for Miley Cyrus fans, on June 24, as well as another edition of “It’s Britney, Boat,” set for July 30.

“I’ll be doing ‘Britney, Boat’ until I’m 50,” he said. “If people are coming, I’m sailing.”