This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
艆 combines 舟 (boat) with 良, but the exact historical development is uncertain. It may have been a phono-semantic compound, but the original meaning is unclear.
The left side is a boat 舟, and the right side is 良 (good). Imagine a good boat, but its exact purpose is unknown.
For ロウ, picture a rowboat: row -> ロウ, and the boat 舟 on the left helps you remember the reading.