My mixed Grade 7-9 class recently completed these watercolour paintings of Viking Longships.
I taught this lesson about 3 or 4 years ago- you can see the steps HERE.
I really recommend using watercolour paper for this- it makes all the difference. This time I tried a 'budget student brand' watercolour paper and it was utter garbage! I mean, it worked enough but not as well as it could have.
Some of the Grade 7 - 9 paintings: