You can connect the speakers of the rowing boat and the kite boat to each other with the M-cable.
1 M-cable is required for 1 speaker.
Connection aid:
2 speakers for 4+ rowing boats
3 speakers for 8+ rowing boats
Nielsen Kellermann does not recommend using more than 3 speakers for older CoxBoxes. If you want to use 4 speakers, connect the speakers to the CoxBox Core or GPS model and make sure you are using the latest speakers.