Every FUSIONSEEKER DS-100S10 and DS-100D10 solar tracker controller can work even under water because its housing is completely watertight. Figure 1 is showing FUSIONSEEKER DS-100S10 "doing his job" under water:
Figure 1: FUSIONSEEKER's underwater test
In this case input voltage is 41,8V (voltage range C), output voltage is 40,6V, output current is 10,50A and instead of a motor bulb is used. Output power (bulb power) is 426W !!!