A crosstransplantation experiment between sites of high (Liliguapi) and low pH (XHuinay) was started in 2014 with specimen of the scleractinian coral Caryophyllia huinayensis. After the initial collection in 2014 the corals were glued onto polyvinylchloride screws in order to be attached to holders that were installed at the collection sites. Originally 20 corals were collected at each site of which 10 were reinstalled at the same site and 10 were reinstalled at the respective other site. To measure the calyx growth from 2015 to 2016, the calyx was photographed in both years using a camera (OLYMPUS digital camera OM-D E-M5, Olympus Corporation, Tokyo, Japan) with a waterproof housing (NA-EM5 Underwater Camera Housing, Nauticam International Ltd., Hong Kong) that was submerged in a black plastic tub. The tub was filled with filtered seawater from the aquarium in which the corals were held during the laboratory work at the Huinay Scientific Field Station. The corals were photographed next to a sliding calliper functioning as scale. The calyx surface area was then measured and calculated from the photos using Photoshop CS6 (Adobe Systems Incorporated, San Jose, USA) and the results from both years were used to calculate the increase in calyx surface area in 2015 - 2016.This dataset was generated within the framework of the co-operation between the Huinay Scientific Field Station (http://www.huinay.cl) and the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (http://www.awi.de)