The latest shipping numbers out of the Strait of Hormuz are offering a timely reminder that the oil market is still a long way from getting an all-clear signal.The preliminary shipping data from Reuters indicated that only ten commodity vessels transited the strait on Wednesday, up from seven a day earlier. That still leaves traffic well below the 10-day moving average of around 17 vessels.Just keep in mind that the usual caveat applies here, as some ships are travelling with their transponders switched off. That means the visible count may not capture everything moving through the waterway.Still, it does provide some indicative feel of shipping flows through the strait. And I would argue that matters when looking at the latest swings in oil prices.Markets have spent much of this week trying to price in the possibility of progress in US-Iran diplomacy. Tehran has said that it remains open to negotiations, with the reopening of the Strait of Hormuz forming part of its proposals. However, the conditions for that to happen don't seem to be aligning as they require the US to also do their part and lift its naval blockade first.In any case, ship traffic continues to underscore the narrative that the physical picture still looks fragile.Brent crude is now trading back above $102 after the overnight surge. And for me, that explains why oil is struggling to settle comfortably below $100.Hopeful headlines on diplomacy can help to take some geopolitical premium out of prices, but shipping data is still telling us that any real form of normalisation has a way to go. This article was written by Justin Low at investinglive.com.