What is the reason that you are not allowed to put your fins on your wrists while hanging on the trail line and have both hands and both feet able to get on the ladder fast? Even in rough seas it is safe and much easier. Boarded boats with closed ladders in 4-6 ft seas like that. A bouncing boat is a beast you want to get both hands and at least one foot on fast. Fins on rule is asking for a lawsuit when the step you should have been standing on takes your chin up over your forehead.
Actually this bolded statement is incorrect. I've seen many people make the same mistake and have had to explain it many times, but often divers will not listen and I can't tell you how many divers I have seen to have "taken it on the chin" (the rung of the ladder that is) by trying to do what you advise.
The most important thing to do when boarding a ladder in rough seas is to time the attack and get on the ladder when it goes down. The diver needs to launch themselves onto the ladder and then STAND UP (on the bottom rung). You do NOT put one foot on the ladder or try to quickly scramble up the ladder. Very few people can support themselves on one leg when the ladder launches them vertically a moment later, using two hands will not help and clinging with the hands or trying to climb with their arms will promote a person slaming their chin into the top rung as they invariably fall from the ladder.
The goal is to get to the ladder, position both feet on the bottom rung in the moment when the ladder is on the down stroke and then very quickly
stand up on both feet on the same rung. Of course you hold on with your hands, but the strength is in the legs and the knees need to be straight to support the diver. Once the diver has both feet planted and the knees locked, he is securely standing on the bottom of ladder, they can then methodically and slowly begin to climb the ladder.
Way too many people try to instantly climb a ladder one foot over the other, when what they need to do is stand up, get on the ladder and then SLOWLY climb. There is zero rush to climb the ladder. The hurry up part is catching the ladder, getting BOTH feet on the bottom rung and instantly standing up. (am I repeating myself?)
Once that is accomplished the diver is pretty safe, they do need to keep their arms kinda straight to keep their face AWAY from the ladder in case a wave comes from behind and tries to throw them forward. If someone is trying to use their arms to climb a ladder, then their elbows are bent and their face is more exposed to being smashed into the ladder from a wave that hits from behind. I learned all this stuff the hard way.
Trying to hang on with one foot and two hands as the ladder thrashes you is a recipe for disaster. If you slip and loose your balance it is much safer to push away from the ladder and allow yourself to fall backwards safely away from the boat and attempt another ascent up the ladder. Trying to hang on after you have partially lost it can allow one foot to slip forward through the ladder, then the diver falls back and they are hanging upside down by one knee from one rung.
If you begin to fall off; allow yourself to do so and PLEASE, push away from the ladder as you fall so it can not come down on you a moment after you hit the water. Then, even though you are scared, pissed and embarassed, do not try to instantly board the ladder. Take a moment or two, to get situated and then make another well synchronized attack on the ladder, when it is on the down stroke.
BTW, the capt. is boss and anyone who tries to help a diver in rough seas by being under them on a ladder is incredibly foolish. Can you imgagine the damage the butt of a tank can do to your head as the diver falls 3-4 feet into you. If the women was weak and had too much trouble, then the scuba unit should be removed in the water and allow her to climb that way.