Abstract: Methods and apparatus for sensing a gauge pressure use a pressure gauge pressure sensor that includes a housing and a gauge pressure sensing element having a first pressure inlet and a second pressure inlet. The first pressure inlet is associated with a pressure to be measured and the second pressure inlet is associated with an atmospheric pressure. A flame arrestor disposed within the sensor housing fluidly couples the second pressure inlet to an internal portion of an explosion proof device.

Abstract: A device for use in human controlled water surface and subsurface travel includes a towbar having first and second end portions. The device includes a first control member that is rotatably coupled to the towbar adjacent to the first end portion and the first control member has a first control surface and a second control surface opposite the first control surface. The device further includes a second control member rotatably coupled to the towbar adjacent to the second end portion and spaced from the first control member, and the second control member has a third control surface and a fourth control surface opposite the third control surface. The device further includes first and second grips spaced apart and fixed to the towbar between the first and second control members so that rotation of the first and second grips about a longitudinal axis of the towbar enables the first and second control members to be independently rotated about the longitudinal axis of the towbar.