Here's an option for the more technical minded folks. The following link is to a firmware binary that will convert any HK "Afro" brand of unidirectional brushless ESC into a reversible one. The firmware should also work on any ESC that uses the "afro_nfet" firmware (a variant of the SimonK firmware). https://www.bluerobotics.com/downloads/besc30-r1/afro_nfet_besc30_r1.hex Besides the firmware file, you will need the KKMulitcopter flash tool and the HK Afro ESC USB programming tool. http://lazyzero.de/en/modellbau/kkmulticopterflashtool http://www.hobbyking.com/hobbyking/store/__67204__Afro_ESC_USB_Programming_Tool_AR_Warehouse_.html Also, you can buy pre-flashed 30A ESC's and fully marinized brushless motors from bluerobotics.com (though the motors need to stay wet or you'll burn the bearings). Have fun!