Diatoms are unicellular algae renowned for their ornate silica cell walls, but equally striking is their ability to adhere and glide rapidly along surfaces—without the use of flagella or cilia. This unique mode of locomotion is central to their ecological success, yet its molecular basis has remained elusive. In this talk, I will present recent insights into the cellular machinery and biomechanics underpinning gliding motility in the raphid pennate diatom Craspedostauros australis. Using high-resolution live-cell imaging and single-cell tracking, we demonstrate that movement is powered by an actomyosin system and that cell trajectories are modulated through a novel switching mechanism between one- and two-raphe substrate contact, governed by local raphe curvature. In addition, through proteomic and evolutionary analyses we uncover a novel family of proteins—Trailins— that contain bacterial-derived domains likely involved in substrate attachment and biofilm formation. Together, these findings shed light on how diatoms navigate their environment—offering broader insights into eukaryotic cell motility in constrained, surface-associated contexts.