Underwater fishing is dangerous, so it is very necessary to make preparations in advance. Before underwater fishing, please use lifting tools to prepare in advance. Next, follow Xiaobian to understand

1. Underwater search: two search team members in each group enter the water in the order planned in advance. The team member who arrives at the bottom table first must wait until another team member a

(1) Investigate the landscape image, water depth, water temperature, flow rate and other environment of the operation area. It can be operated only when the wind force on the water surface is less tha