What is High sea sales and what is de registration

High sea sales means , Goods were sold before it reaches to Custom frentyear , It's nither supply of goods nor services , Schedule III of the CGST act 2017.
please confirm with others also .

Simply, High Sea sales (HSS) is a sale carried out by the actual importer of Goods (ie, the consignee shown in the Bill of Lading) to another buyer while the goods are yet on high seas or after their dispatch from the foreign port and before their arrival at the Indian port.

De registration Means cancellation of registration by any authority, who grant registration.

High sea sales please explain with example

For example, A located in Mumbai procures goods from vendor B of USA.
The goods are exported from the USA and when the goods are in transit (in sea), A enters into a contract with C of Nagpur, and sells these goods to C, before the goods cross the customs frontier of India.
The sale of goods by A of Mumbai to C of Nagpur, while they are in transit is called high sea sale.