Sea freight is one of the most important parts of a supply chain. While moving goods through sea freight, you need to first contact a shipping company. These are big companies and are easier to contact.
Once you come in contact with these shipping companies, you need to instruct them about your product and the weight of your load, the type of goods you want them to transport, and from where you want them to pick up the goods. If you want to send your goods to the shipping company, you can do that too, or just pay a small fee and get your goods picked up from your supplier or from your address easily.
The logic behind the transport of only huge loads is simple, a shipping container is huge enough to transport tonnes of goods, and cannot be used to transport small quantities of goods due to the cost.