There is a new rental place next door to St John Spice (in Cruz Bay by ferry dock) - not sure type of chair they rent, but cost is $45/week ($10/day).
They also rent Snorkel Gear - full set ($45/week), fins or mask ($25/week), GoPros ($150/week), Coolers ($40/week), Umbrella ($30/week), Spring Floats ($30/week), Speakers ($50/week), Boogie Boards ($25/week), and Kid Toys ($25/week). They also have daily prices - these were taken from photo of the store's chalkboard in June 2015.
Also - I hear you can rent at Trunk Bay concessions. I have seen these chairs (not TB).
I love having a TB chair in Maui, but for St John I am okay with lighter weight chairs since there are often cases where I have to carry them moderate distances (e.g. Salt Pond Beach). So - okay with a beater chair.
Importantly - for me - is having a beach umbrella (esp in June). Helps get away from shade given by vegetation (where mosquitoes hang out during day time). I bought a beach umbrella at Cost-U-Less on StT ($30?) - used it for 2 weeks (also used on balcony since ours is in sun now) - and then gave it away to neighbor checking in.
Maho?
Kiddel Bay, chairs great for those beautiful but cobblestone beaches. Me in shade, Robins chair in sun...
Note: WKORV bag, WSJ soft-side cooler, WSJ pool towels, Beach Bar coozies with SN ale in cans, chairs from WSJ FreeCycle, and Umbrella from Cost-U-Less with umbrella tie-down (as discovered on TUG)
one of us is aging better... Chasing down umbrella (thus the tie-down)
speaking of hot... those cobblestones are HOT even with flip-flops
