In my experience, people make passage planning far more complicated than it needs to be. Remember, it is just an overall plan of your intended voyage.
You need to work out rough time of departure, distances etc. but the detailed courses to steer, waypoints and bearing should be done once your voyage is underway. There is no point doing a detailed plan to only find that when you depart the wind direction has changed by 180 degrees!
I always think that passage planning need to be broken into 2 main areas;
One element is the general things that need to be done prior to departure, i.e. boat preparation, crew selection etc. The second is the nitty gritty of the navigational plan. The second element is the one that most people associate with passage planning, but for real, the first element is also important for a successful voyage
This list varies considerably depending on whether we own our own boat or not. If we are familiar with the vessel we are making the voyage on, a lot of these details are known to us already. If we are chartering a boat, there is a lot to find out.
In no particular order;
This list should cover all aspects of the navigation of your vessel. To start with, I have a list of general considerations, followed by a specific set of questions regarding a particular journey.
In no particular order;
Ask yourself these questions for a particular journey. Once you have answered them you will have a workable Passage Plan. Remember this is only a basic overall plan. You only need to work out rough departure times, journey duration and ETA. The details of the journey will be added once under way.
Do your plan BEFORE departure!
I have assumed that we have checked the weather to confirm whether the journey is feasible or not. If it is, look at each of these points;
Are we locked in, if there a sill / bar that restricts access, when can our crew turn up?
Do we need to lock in? can we only access a harbour at certain states of the tide?
Be realistic in average boat speed
If there are, we need to turn up at precisely the right time
Makes sense to travel when the tide is in our favour if possible
Familiarise yourself with rocks, reefs, overfalls, shipping lanes etc.
Where can I go if the weather changes, a crew member gets sick or we have some form of mechanical / electrical breakdown