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An improved watercraft propeller is provided with a hub having a plurality of outwardly extending blades, and at least one reverse thrust member connected to a selected blade of the propeller. The blade to which the reverse thrust member is connected can provide a blade pitch that is constant, varia

An improved watercraft propeller is provided with a hub having a plurality of outwardly extending blades, and at least one reverse thrust member connected to a selected blade of the propeller. The blade to which the reverse thrust member is connected can provide a blade pitch that is constant, variable, progressive, or regressive. The reverse thrust member is formed integrally with or connected to a leading edge of the selected blade. The reverse thrust member effectively increases the pitch of the propeller when operated to propel a watercraft in a reverse direction, thereby improving the performance and efficiency of the propeller.

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An improved watercraft propeller is provided with a hub having a plurality of outwardly extending blades, and at least one reverse thrust member connected to a selected blade of the propeller. The blade to which the reverse thrust member is connected can provide a blade pitch that is constant, varia

An improved watercraft propeller is provided with a hub having a plurality of outwardly extending blades, and at least one reverse thrust member connected to a selected blade of the propeller. The blade to which the reverse thrust member is connected can provide a blade pitch that is constant, variable, progressive, or regressive. The reverse thrust member is formed integrally with or connected to a leading edge of the selected blade. The reverse thrust member effectively increases the pitch of the propeller when operated to propel a watercraft in a reverse direction, thereby improving the performance and efficiency of the propeller. e diffuser slot is positioned to capture a part-span vortex in the fluid thereby at least partially collapsing the vortex. 9. A device as in claim 1, wherein said at least one diffuser slot does not have a constant width. 10. A device as in claim 1, wherein the fluid flow is under a static pressure and said at least one diffuser slot is configured such that the static pressure in the fluid flow is sufficient to move the fluid flow from said at least one diffuser slot to said at least one passage. 11. A device as in claim 1, wherein said at least one diffuser slot is oriented so that it is no more than 65 degrees from radial with respect to said axis. 12. A device as in claim 1, wherein said at least one diffuser slot is oriented so that it is no more than 10 degrees from radial with respect to said axis. 13. A device as in claim 1, wherein said device includes at least two diffuser slots. 14. A device as in claim 13, wherein at least one of said diffuser slots is located adjacent a leading edge of the blades. 15. A device as in claim 13, wherein at least one of said diffuser slots is located adjacent the housing exit. 16. A device as in claim 13, wherein at least one of said diffuser slots is located adjacent the blades downstream of a leading edge of said blades. 17. A device as in claim 1, further comprising: a) a particle capture slot in fluid communication with said at least one diffuser slot; and b) a particle trap in fluid communication with said particle capture slot. 18. A device as in claim 1, wherein the device includes a means for maintaining or increasing the static pressure in the fluid flow as the fluid flow flows through the device. 19. A device as in claim 1, wherein the device includes a means for directing fluid from said at least one diffuser slot to multiple areas within or outside of the housing. 20. A device for at least partially stabilizing an unstable fluid flow within a flow channel, the device including an inducer or impeller residing at least partially within the flow channel, the inducer or impeller having rotatable blades for drawing the flow into, or being driven by the flow in, the flow channel, the inducer or impeller rotatable about an axis, the flow channel defined by interior sidewalls of a housing, the housing at least partially surrounded by an inlet plenum, the housing including an exit, said device comprising: a) at least one diffuser slot, said at least one diffuser slot including an inlet and an exit, said inlet in fluid communication with the flow channel, said at least one diffuser slot being substantially radial with respect to the axis; b) a re-entry slot in fluid communication with said at least one diffuser slot and the flow channel; and c) a return slot in fluid communication with said at least one diffuser slot and at least one of (i) the inlet plenum and (ii) the housing exit; wherein said at least one diffuser slot is free of vanes and said at least one diffuser slot has a width of about (0.05 to 0.50)×(the radial height of said impeller or inducer blades at said at least one diffuser slot inlet). 21. A device as in claim 20, wherein said at least one diffuser slot has a radius ratio greater than 1.03. 22. A device as in claim 20, wherein said at least one diffuser slot has a radius ratio of about 1.07 to about 2.00. 23. A device as in claim 19, wherein the inducer or impeller rotatable blades have a leading edge and said at least one diffuser slot inlet has a longitudinal center-line that intersects the flow channel at a point along the sidewalls, the distance from said point to the leading edge being up to 70% of the radial height of said impeller or inducer blades. 24. A device as in claim 19, wherein said at least one diffuser slot is sized so that the flow through said at least one diffuser slot is from about 1/2%-15% of an overall flow through said flow channel at the best operating point within the channel. 25. A device for at least partially stabilizing