Diver Frogman Service Company - Hengrui Underwater Engineering Co., Ltd. On April 12, 2022, the underwater drilling, rebar planting and concrete pouring of Haikou Huacai Plaza wharf were successfully completed. The project site is located in Haidian Island, Haikou City, Hainan Province. The Huacai Plaza project has a rebar diameter of 25 and underwater drilling