Just after school started, Xia Weixing, director of the Navigation Teaching and Research Office of the Naval Submarine Academy, smiled after finishing the statistics of the latest data of the quality indicators of maritime teaching in recent years. "Since 2019, the average annual growth rate has been 7.8%." Xia Weixing said that the excellent rate of the students' comprehensive scores in the three main examinations of navigation practice. The annual navigation practice has never been interrupted since the school was founded. The scores that have been continuously improved in recent years show that this routine maritime training is breaking the cycle of "self-replication". Why can our achievements improve rapidly in recent years? "The team has made great contributions to the innovative development of the 'blind box' at sea in the past few years," said Xia Weixing, who has just completed the new year's navigation practice plan. With that, Xia Satellite opened a group of pictures on the computer to elaborate on the origin of the "blind box". The warship carrying the training shelter is on the voyage. A few years ago, there was a popular saying among students about sailing practice: "In the wind and waves, the shed is waiting for you.". As long as the ship is not docked or anchored, the students will carry out chart work in the chart shed, one for each person and one for half of the body. The small chart shed witnessed the track of a group of students to the battlefield, and also witnessed their experience of fighting with the sea. In September of that year, the warship that supported the internship sailed to the South China Sea, and the maximum temperature on the deck exceeded 50 ℃. The trainees were confined in the shed, with wet towels hanging on their necks and irregular patterns of different sizes on the chart - sweat stains. The team leaders carried cold buckets to wash the towels for the students one by one. At the same time, the voice of the instructor came from the speaker: "The more severe the heat is, the more challenging our fighting style is." On the surface, the "stove" is ambitious and powerful, but in fact, the training effect is not ideal. "There is not enough modern means of navigation support, and there is no efficient special training system. It just depends on the will to fight with the sea." Professor Yang Xiaodong, then director of the navigation teaching and research section, thought alone on the deck, and an idea came to mind - teaching reform. Another day after the training, Yang Xiaodong chatted with a leader of the cadet brigade in the "radar room" when the ship was anchored. The radar room is a small iron room specially built for radar receivers and other equipment. "Professor Yang, how many times have the tall houses in Nansha been upgraded? We are still guarding the chart shed decades ago. Even if we can live in this kind of iron house, at least we are not afraid of the wind and rain..." The leader of the brigade inadvertently woke up Yang Xiaodong. At the end of the internship, taking the "radar room" as a sample, Yang Xiaodong began to look for a shelter or plank house suitable for building on the deck as soon as he returned to the college. In fact, it is the college that can enable students to carry out navigation training on a platform that is closer to the actual installation of submarines, closer to the actual combat environment and closer to the direction of educational reform