This is by Konrad Starke, an artist I could find nothing about on the internet except that he was born in 1870 and died in 1911, an unfortunately short lifespan.  The title actually comes from the French word ‘dilettante’ which means a dabbler or novice in some activity, usually in the arts but in this case the “art” of rowing a boat.

Konrad Starke – Dilettanten – Jugend No. 51 (1897)