Yes same explanation for the arancias the lifeguards use . However a little 30 hp that lives on the beach and is used hard in surf every day isn't the same as a d class or similar boat that's returned to the station after each launch and lovingly cared for . The twist throttles and cables very soon become sticky on a beach environment .all that is fitted is a single return spring hooked to the throttle linkage and bolted to the casing , the kill switch is removed and replaced with an on off switch.
Also same system us being used by the surf life saving clubs which rely on volunteers for maintenance and they even race the boats .
Iam not out to knock the rnli or the lifeguards but the system is wrong IMO and I have seen close mishaps on our local beach . not even the fastest swimming lifeguard can catch a sib ticking over in gear in the surf .
A kill cord worn on the wrist of the throttle hand will stretch a long way from the throttle. Once you are that far away from the tiller you have lost control anyway