Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Date | Ship | Type | Nationality | Tonnage GRT |
| --- | --- | --- | --- | --- |
| 11 Jan 16 | Corbridge | Cargo ship | United Kingdom | 3687.0 |
| 11 Jan 16 | Farringford | Cargo ship | United Kingdom | 3146.0 |
| 13 Jan 16 | Dromonby | Cargo ship | United Kingdom | 3627.0 |
| 13 Jan 16 | Author | Cargo ship | United Kingdom | 3496.0 |
| 13 Jan 16 | Trader | Cargo ship | United Kingdom | 3608.0 |
| 15 Jan 16 | Ariadne | Cargo ship | United Kingdom | 3035.0 |
| 15 Jan 16 | Appam | Cargo ship | United Kingdom | 7781.0 |
| 16 Jan 16 | Clan McTavish | Cargo ship | United Kingdom | 5816.0 |
| 22 Jan 16 | Edinburgh | Sailing ship | United Kingdom | 1473.0 |
| 4 Feb 16 | Luxembourg | Cargo ship | United Kingdom | 4322.0 |
| 6 Feb 16 | Flamenco | Cargo ship | United Kingdom | 4540.0 |
| 8 Feb 16 | Westburn | Cargo ship | United Kingdom | 3300.0 |
| 9 Feb 16 | Horace | Cargo ship | United Kingdom | 3109.0 |
| 24 Feb 16 | Maroni | Cargo ship | France | 3109.0 |
| 25 Feb 16 | Saxon Prince | Cargo ship | United Kingdom | 3471.0 |
Question:
what is the tonnage grt of the ship author?
Answer:
3496.0