In order to become an ordinary seaman (OS), it can help to have some specific skills and characteristics. A great deal of knowledge about seamanship is not typically necessary, since these jobs tend to involve a lot of on-the-job training. It is important to be in good physical condition though, and you should also have the ability to understand and carry out complex instructions. Good organization skills and communication abilities are also important, as you will typically work in all different areas of the ship. In addition to these basic skills and abilities, you will also need to obtain the specific certificate or credential required in your country.
The position of ordinary seaman is an apprenticeship role that can allow you to gain the necessary sea time required to sit the able seaman (AS) exams. It may be possible to obtain this type of job with no specific work experience or higher education, though you will typically need to be at least 18 and have graduated from high school. It is also necessary to obtain a merchant mariner's credential (MMC), OS certificate, or whatever similar paperwork is required in your country. In order to obtain these documents, you will usually need to prove your citizenship, pass a physical, and submit to a drug test.
As an ordinary seaman, you will be expected to perform a wide range of duties throughout a ship. The most important skill or characteristic needed under those difficult circumstances is physical fitness. You will typically be required to do maintenance work, including sweeping, mopping, descaling, and painting decks and other portions of a ship. Depending on the ship you work on, you may also need to handle cargo, splice and knot ropes, and perform other tasks that require physical strength, stamina, and dexterity. You will further need the ability to understand and carry out complicated orders due to the wide range of duties you are likely to be responsible for.
Even though there are no specific educational requirements, other than a high school diploma, it can help to have a solid understanding of basic math before you become an ordinary seaman. If you take classes in trigonometry in high school, you may have an easier time plotting courses and performing other similar tasks. It is also important to have strong written and oral communication skills if you want to succeed as an ordinary seaman, so you may want to take those types of classes if you have trouble speaking or writing clearly.