This business of 'The other type has a pause between forward and reverse.' is rapidly becoming an old chestnut!!
If you look in the instructions for the Car ESC (such as the Hobbywing 16BL30 which I use in my Sea Scout - instructions in attached PDF) you will find that you can change the Running Mode from the Default Car mode 'Option 2 FWD/STOP/REV' to instant reverse by setting to 'Option 3' FWD/REV.
You can also programme the start mode to smooth out the 'jump starts' that I've seen others complain of with brushless motors.
You CAN do all this using the TX and listening to Beeps and watching flashing LEDs but it's much easier if you buy the little Programming card for the ESC.
Usually only a few quid (maybe a few more bucks😉) but very easy to use.
Cheers, Doug 😎