Belowdecks, the 4300 Open boasts more leather and wood than a Renaissance festival. She’s spacious, not just because of her brawny dimensions, but also because of the way in which Tiara expanded the envelope. First, the chines run far forward before breaking the waterline. That increases width at the cabin sole in the forward sections. Second, the height of the cabin trunk provides enough headroom for an NBA player, yet doesn’t cause the boat to look like his high-top sneaker: The flow of the sheer, the way in which the windshield runs right up to the underside of the hardtop, and other design legerdemain ensure the sleek look of the 4300 Open.