The Cornish Gig oar by Collars:  https://www.youtube.com/watch?v=c6haJElXSvQ

Understanding the Greenland Paddle: https://www.youtube.com/watch?v=-jgWn7BaGSw

Annapolis Wherry Tandem: https://www.clcboats.com/shop/boats/rowboats/annapolis-wherry-tandem-rowboat.html  Building Video: https://www.youtube.com/watch?time_continue=1&v=ExFqOgdQOuQ&feature=emb_logo  Using it: https://www.youtube.com/watch?v=n8Ph48NO0co&feature=emb_logo