Not even the most inexperienced sailor would not wear a life vest during the storms or when he was afloat. The life vest is one of the most basic items that sailors use on those situations.
The second time the boat does a complete roll the hatch to the cabin is completely open, yet when the man returns to the cabin the floor is completely dry. Water would have poured in through the open hatch until forming an air bubble at the bottom of the hatch (then upside down).
Early on, "Our Man" is shown shaving with a manual razor and shaving cream. Over the next 8 days, much of that time fighting for his life in a small inflatable lifeboat, his face and chin remain smooth, with no signs of any stubble.
When then man puts on his storm suit and goes out to raise the storm jib he is tossed off deck and dragged underwater. He climbs back on board and returns to the cabin. When he removes the top of the storm suit his shirt is completely dry.
When Our Man deploys his sea anchor from the stern of the boat, the yacht should immediately swing round in the gale, presenting its stern to the wind, yet we see Our Man continues to get lashed with rain blown from the bow.
It is not really correct to call "SOS" on the marine emergency radio channel. "Mayday" or "Pan Pan" would be accurate and standard forms whereas "SOS" will be understood but is incorrect. A veteran sailor would never have made this mistake.
When the boat is dismasted, "our man" uses a knife to cut the shrouds (i.e., the metal wires) that are still linking the stump of the mast to the section that is lying in the water. This is impossible, since only a bolt cutter with a long handle could do the job.
During the storm, "our man" picks up a bag with the "storm jib" label and then fights against the elements to hoist this sail. However, the sail in question is not a storm jib at all. It is very large, light and white, whereas storm jibs are small, heavy and brightly colored.
Our man goes aloft to repair his boat's antenna, and sees a storm approaching. But the storm should be moving away from him, because it is downwind (according to the wind vane visible in the shot).
On the boat during the storm, "our man" ties the floating anchor to the aft (rear) pulpit. Given the huge forces involved, the pulpit would have been bent and ripped away in seconds. A similar comment could be applied when he ties his lifeline to the guardrails.
When the container is embedded in the side of the yacht at the start of the film, our man deploys a sea anchor to drag the container away. As the container and the sea anchor are being moved by the same ocean, the sea anchor would just sink and not exert any useful force on the container.
No experienced seaman would ever be so relaxed about the large amount of water pouring into their boat, especially so far from land.
If he deployed a "sea anchor" which he used to remove the container from his boat, why did the rope remain relatively flat after the container was pulled from the boat? Wouldn't the rope be seriously pulling "straight down?"
When Our Man is waving at the passing ship you can see land in the distant background despite the fact that the raft is supposed to be in the middle of the ocean.
After retrieving his sextant from the sinking sailboat, Our man opens the dry cardboard box in his life-raft.
Computer/Credits
Day 1: Wading in thigh deep flooded cabin to find fiberglass hull repair kit
"Our Man" picks up a Panasonic "Fully Rugged" Toughbook laptop, examines it,
lays it open and flat to dry. Waterproof and washable (popular at sea) it'd likely be undamaged by flooding.
When his boat rolls over the first time in the storm after it rights itself, one can see one of the portholes is open. This would have caused a lot of water to enter the cabin, which is not visible.
When our character drinks the sea water, after attempting his desalination technique, he checks his watch (seiko skx009) to see the time but it is actually worn in the wrong way.
The crown is in the wrong place therefore he would see the time upside down.
When our character attempts to use the radio transmitter/receiver you can see a shot of his watch. The seconds hand is not moving.
When Our Man leans over the railing to inspect his hull repair for the second time, support craft are briefly visible on the horizon.
When 'our man' discovers he has no drinkable water and discards the jerry-can, we follow the action and see the knee of the camera operator. Bottom left frame, in jeans.
When crossing a large body of water, a rainstorm would be seen as an opportunity to wash off all the accumulated salt - the character would have undressed and lathered up immediately rather than just rolled up his sleeves. It may even be the first proper wash a sailor would have had in weeks, due to the limited supply of fresh water aboard.
When "Our Guy" (Redford) uses the radio, he tries to speak in the wrong side of the handheld microphone. He tries to talk into the metal latch, covering up the actual microphone opening with his hand. Any experienced seaman would never make this error.
When "our man" leaps aboard the inflatable life raft during the tempest, he neglects to untie the tether to the sinking sailboat and proceeds to ride out the storm before falling asleep. He awoke the next morning to find the boat still afloat and tether intact. The boat ends up protesting its own buoyancy minutes later after he decides to re-board and fetch more supplies, but could certainly have sunk hours sooner.
Although the part for "our man" was written to present the character as errant in certain scenes, no seasoned sailor would have made this mistake.
Although the part for "our man" was written to present the character as errant in certain scenes, no seasoned sailor would have made this mistake.
At no point during any of the rain, storms or heavy wind, does our hero raise the spray hood.