Blake – WOW – a difficult one.
I hope you have read Please read this first - Please! - any interpretation given is the best we can do and should not be taken as authoritative. They are suggestions given hopefully to help you find a greater insight into yourself. And even that is only a faltering step toward a full understanding of your dream. A dream, even a simple one, is a thing of wonder. The images in it are simply covers of massive books of information - or like a photograph of a living person. In other words the dream does not become alive until you yourself enter it. So some people will want to find that wonder, and can do so through using
http://dreamhawk.com/dream-encyclopedia/acting-on-your-dream/#BeingPersonI point that out because of what I am about to say.
The context of your dream says the boat is the vehicle you make the journey of your life in. It has been well kept because was new when you were born. The people coming and going are the many people who had an influence in your life.
Then the boat was going down, suggesting that you are old and nearing the end, or you haven’t looked after you body and you must make repairs. Perhaps watch this documentary
https://www.youtube.com/watch?v=uxqOIJWOWXk The boat going high might suggest that you have pushed yourself to achieve something, either intellectual or spiritual, but it hasn’t worked. This may be because all life is dual and we exist strung between enormous duality – sleep and waking, male and female, pain and pleasure, light and darkness, life and death, and death and resurrection, war and peace, matter and anti-matter, negative and positive, the void and bodily existence. To be whole we need to accept and meet these opposites. See
https://dreamhawk.com/approaches-to-being/opening-to-life/ Tony