ESC calibration for boat

Hi! I’m trying to set up a boat with two motors. ESC’s have forward and reverse directions. How to calibrate Pix and ESC?
I disabled ARMING_REQUIRE and BRD_SAFETYENABLE, but the motors start almost instantly without going into calibration mode.
My equipment: FrSky X4R, Pixhawk 2.4.8, Radiomaster TX16S.

I encounter the same problem, impossible to set up the new ESC in order to have the maximum power available for the engines.
The ESc work well (forward and backward) but the boat goes slower than before in manual or car (I did not change anything else).
I changed ESC because those of 30A overheated (melting of the insulation), the new ones can take 60A.
Did you find a solution?
Best regards

I calibrated the ESC separately, right on the receiver. Then I connected it to Pixhawk.