> For the complete documentation index, see [llms.txt](https://docs.dataloy.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.dataloy.com/release-8.28/voyage-management-system/step-by-step-guides/master-data/vessel-types/maintain-opex-on-a-vessel-type.md).

# Maintain OPEX on a Vessel Type

Vessel Type records carry a list of default OPEX lines. These represent the standard running cost structure for all vessels of that type and serve as the baseline that is stamped onto voyages when a vessel of this type is assigned.

***

### Opening the OPEX List

Navigate to the Vessel Type. The Default OPEX list is displayed within the Vessel Type drawer.

***

### Adding an OPEX Line

**1. Click Create** in the Default OPEX section.

**2. Enter the required fields:**

| Field                     | Description                                                                                                  |
| ------------------------- | ------------------------------------------------------------------------------------------------------------ |
| **Opex Cost Code**        | Reporting code for this cost category. Used for consistent reporting across vessel types and vessels.        |
| **Opex Cost Description** | Name of the cost category, e.g. "Crewing", "Lube Oil", "Insurance".                                          |
| **Daily Rate**            | Cost per day in the OPEX currency.                                                                           |
| **Currency**              | Currency of the rate. Defaults to the company currency. \[⚠ inferred — confirm default]                      |
| **From Date**             | Start of the validity period for this rate.                                                                  |
| **To Date**               | End of the validity period. Leave blank if the rate is open-ended. \[⚠ inferred — confirm if blank is valid] |
| **Stock Account**         | Accounting stock account for posting.                                                                        |
| **Cost Account**          | Accounting cost account for document lines.                                                                  |
| **Comment**               | Optional free text.                                                                                          |

**3. Save.** The line is added to the list.

***

### Editing an OPEX Line

All columns are editable directly in the list, except the Opex Cost Code column, which is read-only once created.

***

### Deleting an OPEX Line

Select the line and click Delete. Deleting a line from the Vessel Type does not affect OPEX lines already stamped onto existing vessels or voyages.


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