If you think you're close to the text you want to see, don't try a fancy search—use the PGUP or PGDN key. It's often faster. One trick you can use to speed up this method of searching is to leave a trail in the form of marks (names associated with file locations).
PWB lets you set named marks at any location in your file by using the Define Mark command from the Search menu or by using the Mark function. You can access these locations by name using the Goto Mark command or the Mark function.
For example, if you are revising a preexisting program and don't fully understand all the algorithms, you might leave a mark at each location in the code you want to examine more closely. That way, you can revise the sections of the program that you do understand, get a feel for the flow of the program, and then come back to the marked areas for further research.
To save marks between PWB sessions, create a mark file using the Set Mark File command from the Search menu.