One can only presume your Grace is looking for funds for a new clerestory roof to the castle's lavatory block, or something, because if it pleases your Lordship, the submarine is most definitely resident amongst your Grace's vehicular modes of transport at your Lordship's stables.
Viz:
Lord SanDisk, 18354, civ, I_SDV_01_F, Ship, 76561197966795594, 1, 0, 779576, 0, "[]"
Perhaps your Lordship's valet took it out for a spin and didn't bring it back in time before you happened to peek into the shed?
However, maybe your Grace is offering to surrender the vehicle out of a sense of duty and public good - and we would most humbly accept the offer, given that it is indeed true that vessels of the submarine kind are causing no end of problematic audit-trail and overly complicated accounting practices to be lodged in the daily record of Altis Life (aka, the Logs).
If you wish the vessel to be destroyed, and the money refunded, I will oblige forthwith upon your signal, my Lord. Alternatively, you may wish to simply retain charge of the (unused) vehicle, safely stored under lock-and-key in your Lordship's marina, in the hope that it returns to full working order one day, but bear in mind we are very much dependent upon the auspices of those Bohemian artisans for this occurence, and my Lord knows what they can be like.
Respectfully yours, I remain, your obedient servant, etc., etc.