The Transcendent Border wasn't overbearingly luminous, but it was still bright enough that they should have seen it from a greater distance, considering how large it was. Even the others, who didn't see the bright flash of dazzling rainbow mana since they didn't have anything similar to Toz's mana vision, should still have seen it from far away. After all, most of them spent a lot of time on deck. There was no way they could have missed it unless they closed their eyes.
Even if they closed their eyes, they would have still sensed the pressuring calm in the air that affected them all equally, even if they were at the transcendent level or not.
But as Toz and the cats walked onto the deck, they noticed that the others had just noticed or were away fetching the ones who hadn't noticed.