  Significant work has been done on advancing localization and mapping in
underwater environments. Still, state-of-the-art methods are challenged by
low-texture environments, which is common for underwater settings. This makes
it difficult to use existing methods in diverse, real-world scenes. In this
paper, we present TURTLMap, a novel solution that focuses on textureless
underwater environments through a real-time localization and mapping method. We
show that this method is low-cost, and capable of tracking the robot
accurately, while constructing a dense map of a low-textured environment in
real-time. We evaluate the proposed method using real-world data collected in
an indoor water tank with a motion capture system and ground truth reference
map. Qualitative and quantitative results validate the proposed system achieves
accurate and robust localization and precise dense mapping, even when subject
to wave conditions. The project page for TURTLMap is
https://umfieldrobotics.github.io/TURTLMap.
