Tuesday's crew weigh-in on Nisida was dockside, methodical, and purely business for the AC40 teams gearing up for PR2 Naples. But behind the routine lies a rule that shapes every start line in this competition.
One-design racing lives and dies on rules like these. The AC40 class wants racing decided by sailing skill, not by which crew happens to be lighter, and that means weight has to be equalised across every boat.
The number that matters is 360kg. That's the all-up crew weight stipulated in Clause 3.6 of the AC40 Class Rule, published on the Official Noticeboard, for the four-person crews, with each sailor approximated at a maximum of 90kg. That figure isn't just bodies, though. It covers "carried equipment and crew media equipment" too, everything from helmets and knives to microphones, headphones and air canisters.
So what happens when a crew comes in light?
Given the physical condition of today's America's Cup sailors, that's the norm rather than the exception. Gym sessions every morning, relentless conditioning programmes, strict fitness routines. Most sailors sit well under the 90kg (14.17 stone) mark even once their gear is added in.
The rule book has an answer. Clause 3.7 requires that lead shot ballast be added after weigh-in, bagged and fixed to the seat plinths of each crew member, to bring the total up to that 360kg benchmark. The placement isn't random either: the rule calls for ballast to be distributed so the combined centre of gravity of crew and lead, once everyone's sitting in their seats, matches as closely as possible what you'd get from four 90kg sailors.
Once it's in, it stays in. Clause 3.8 is blunt about that: "Ballast or other equipment shall not be moved for the purpose of changing trim or stability." No shuffling lead around the boat to chase an edge mid-series.
There's more fine print governing personal kit. Clause 10.5 sets carried equipment at 5.0kg dry, rising to 8.0kg "when soaked and allowed to drain for 1 minute." Clothing designed to hold water to bulk up that figure isn't permitted either.
What actually came out of Tuesday's weigh-in, team by team, isn't public. There's no shortage of speculation around the docks about which crews needed more correcting lead than others.
That detail, like plenty else in this Cup cycle, stays behind closed doors.
