Hi James. Welcome to G2G!
There are eight images from Wordsworth's manuscript for The Prelude at this British Library link. Unfortunately they are copyright. If you look through them perhaps you will find part of the rowboat sequence.
A better bet may be the third image at The Boat Stealing Caper (also marked copyright). It does seem to show part of the manuscript relating to the rowboat, but the resolution is quite poor.
Edited to add: The British Library image viewer works poorly on an iPad, but it does look as if at least the first two images relate to the rowboat. The handwriting is not Wordsworth's, but that of his wife Mary.
There are 243 different pictures located on this site that may have what you are looking for and hopefully this response will help you towards finding success with your search. If I see anything elsewhere I’ll comment again under your post with the information.
Melissa
https://www.gettyimages.com/photos/william-wordsworth
Check this out, I know it’s not exactly what you are looking for, but it’s still worth taking a few minutes to watch.
https://youtu.be/7LruI4IaCAI