To me, the biggest difficulty with analogies like this is the conflation of the Church (aka “The Ship Zion”) and the “Iron Rod” (aka “The Word of God”, aka Jesus Christ).
The Church is like a ferry connected to the Iron Rod, at some unknown distance (or not at all if you so believe). At times, the ferry is close, other times further, but it is still connected and going toward the Tree of Life.
One problem comes in that not everyone can see how far or how well the connection is all the time. We can trust Prophets, the laying of the ferry keel, our own “eyeballing”, and/or whatever answer we get through prayer, but throughout we’ll make judgments as to our comfort with how well and how far from the Iron Rod is appears to us the ferry is at any given time.
Another problem is that the ferry is full of people, some steering, some pushing, some merely riding, some trying to call or use sticks to reach out and help others in, some unintentionally driving people away with those sticks, some even intentionally driving people out and away. Each of us has their own perspective on the water worthiness, condition, direction, and population of the ferry.
But no matter how connected the ferry, it is -not- the Rod. Other ferries have their own connection to the Rod. Individuals can cling to the Rod on their own or even press forward as near as they can to it. They can even have their own ships moving in the right direction, with no knowledge of the Rod.
Our job is to help improve the connection of the ferry to the Rod, improve it’s condition, change or remove those who are diving others out and away (and sometimes the enemy is us), and to invite others to come aboard. The ferry may make it easier for us, but it’s just a conveyance, and it will not suit everyone. If we want more to join us, we should be looking for what can be improved, as it has been improved upon in the past.
Above all that, however, we need to be directing others to the Iron Rod, no matter what the conveyance or lack thereof.