I guess that depends on how fast you can make the cable; I have no idea how that pans out - but the cable is put onto the vessel straight from the production line (which, I guess, may have had its speed optimised to the speed at which crews can reliably put down cable.)
I am now curious; I'll fire off an email with a few questions to my liaison at TE SubCom. With any luck, answers arrive in time to be relevant to this thread.