Final answer:
To make Joan as safe as possible right away, Bill should position her on her side to ensure her airway is clear and monitor her condition closely. This is a universally recognized precaution to prevent choking or aspiration. Seeking medical attention should be a priority if her condition seems serious.
Step-by-step explanation:
If Bill is concerned about Joan's immediate safety, the best action he can take is to position her on her side and watch her while she sleeps. This measure is often recommended in situations where a person may be at risk of vomiting while unconscious or semi-conscious, which could lead to choking or aspiration if they are not lying on their side. Moreover, it is essential to monitor the individual to ensure that their condition does not worsen.
Moving her to a bed inside the boat's cabin may provide comfort but does not ensure safety from potential choking hazards. Waking her up and giving her some black coffee is not an appropriate immediate action for safety, and may be harmful if she is not in a state to safely consume liquids. Making her take a cold shower could be dangerous if she is not fully conscious and able to maintain her balance.
It is crucial to keep in mind that if Joan's condition seems serious, seeking medical attention should be a priority. However, without more context, it's difficult to provide a definitive answer but ensuring her airway is clear by positioning her on her side is a universally recognized precaution.