The Sea Service Calculator helps seafarers, officers, marine students, and shipping professionals calculate their total sea time duration with complete accuracy. You can enter multiple assignments with joining and leaving dates, and the tool automatically calculates your total service time in years, months, and days.
This calculator is especially useful for:
- STCW certification
- Seafarer rank upgrades
- Visa documentation
- Maritime academy requirements
- Shipping company job verification
- Sea time eligibility checks
With fast and accurate calculations, this tool saves time and ensures precise results for all maritime professionals.
What Is Sea Service?
Sea service refers to the total number of days a seafarer has spent working on board a ship. This time is officially counted for:
- COE (Certificate of Endorsement)
- COC (Certificate of Competency)
- Promotions and rank upgrades
- Maritime license renewals
- Training eligibility
- Company service records
Sea service is typically calculated using joining and leaving dates across multiple contracts.
Why Sea Service Calculation Is Important
Required for promotions
Ranks like Officer, Chief Officer, Captain, 2nd Engineer, and Chief Engineer need a minimum sea time.
STCW training eligibility
Courses like OIC, ECDIS, GMDSS, and advanced modules require sea service.
Mandatory for license renewal
Maritime authorities check total sea time.
Employer requirement
Shipping companies verify your sea days before hiring.
Visa & immigration
Some countries require proof of sea time for seafarer visa processing.
How the Sea Service Calculator Works
You can add multiple assignments. For each assignment:
- Enter Joining Date
- Enter Leaving Date
The tool calculates:
- Total days for each assignment
- Combined sea service
- Total in years, months, and days
- A breakdown of each contract
This gives you a clear, professional summary useful for applications and documentation.
Sea Service Calculation Formula
Below is the simple formula:
- Convert each date range into days
days = leaving_date − joining_date - Add all assignment days
total_days = sum of all assignment days - Convert total days into years, months, and days
years = total_days / 365
months = (remaining days after years) / 30
days = final remaining days
This gives the final sea service duration.
Example Sea Time Calculation
Assignment 1:
Joining: 01 Jan 2024
Leaving: 01 Apr 2024
Duration: 90 days
Assignment 2:
Joining: 01 Aug 2024
Leaving: 01 Nov 2024
Duration: 92 days
Total days = 90 + 92 = 182 days
Conversion:
- Years: 182 / 365 = 0 years
- Remaining: 182
- Months: 182 / 30 = 6 months
- Remaining: 2 days
Final Sea Service: 0 years, 6 months, 2 days
Who Can Use This Sea Service Calculator?
👨✈ Deck Officers
Calculate sea time required for competency exams or promotions.
⚙️ Marine Engineers
Track service days for license renewals or rank upgrades.
🧭 Ratings & Crew
AB, OS, Motorman, Wiper, Cook, Fitter, etc.
🏫 Maritime Students
Use it for academy training & mandatory sea time records.
🚢 Shipping Companies
Verify candidates’ sea service quickly.
Benefits of Using the Sea Service Calculator
- Fast and accurate
- Accepts multiple assignments
- No manual date calculation
- Clean breakdown of sea time
- Year-month-day format
- Ideal for official record preparation
FAQ – Sea Service Calculator
1. Does the calculator count both joining and leaving days?
The calculation is based on the date difference. If your maritime authority counts differently, adjust accordingly.
2. How many assignments can I enter?
The tool supports multiple entries (5 by default). More can be added on request.
3. Is this calculator accurate for official documentation?
Yes, it uses standard day calculations; always verify according to your company/flag state policy.
4. Can I calculate short contracts?
Yes, even one-day assignments can be calculated.
5. What if the leaving date is earlier than the joining date?
The tool automatically ignores invalid entries.
