In 1888 Wyllie made his third cruise on the Dutch canals in the yawl 'Ladybird' in preparation for an exhibition of 62 watercolours later that year, 'Netherland Waterways', commissioned by Robert Dunthorne for his Rembrandt Gallery, London. He was accompanied by his wife – who wrote an account of the cruise, 'The Log of the Ladybird' – and their seven year old son, Harold.
Mrs Wyllie later wrote that, as they approached Middelburg:

'We set sail and ran up the canal, through a great swing bridge which gaped ponderously, as the bridge-master hove round with a hand-spike, and we brought up for the night near two queer-looking tjalks, whose skipper told us that if we did not show a light, '”Policeman come round, pay plenty money.'”

The term 'tjalk' is not a name for a distinct class of craft, but for a group of broad, barge-type vessels used for carrying cargo that originated in Friesland at the end of the 17th century. They were flat-bottomed and, by the 19th century gaff-rigged.

M.A. Wyllie, ‘We Were One’ (London: Bell & Son Ltd., 1935)