frequent disk error, need guidance

I'm seeing a boatload of the same error:
   (ada0:ata2:0:0:0): READ_DMA. ACB: c8 00 e2 c7 73 41 00 00 00 00 40 00
   (ada0:ata2:0:0:0): CAM status: ATA Status Error
   (ada0:ata2:0:0:0): ATA status: 51 (DRDY SERV ERR), error: 40 (UNC )
   (ada0:ata2:0:0:0): RES: 51 40 e7 c7 73 01 01 00 00 00 00
   (ada0:ata2:0:0:0): Retrying command, 3 more tries remain
repeated, with occasional:
   g_vfs_done():ada0p2[READ(offset=12474351616, length=32768)]error = 5

# smartctl --info /dev/da0
   Model Family:     Seagate Barracuda 7200.9
   Device Model:     ST3808110AS
   Serial Number:    4LR1HW1E
   Firmware Version: 3.ADH
   User Capacity:    80,000,000,000 bytes [80.0 GB]
   Sector Size:      512 bytes logical/physical
   Device is:        In smartctl database 7.3/5319
   ATA Version is:   ATA/ATAPI-7 (minor revision not indicated)
   Local Time is:    Fri Apr 14 09:43:01 2023 MDT
   SMART support is: Available - device has SMART capability.
   SMART support is: Enabled
# smartctl --health /dev/da0
   SMART overall-health self-assessment test result: PASSED

# smartctl --test=long /dev/ada0
# smartctl --log=selftest /dev/ada0
Num  Test_Description                          Remaining  LBA_of_1st_error
                        Status                        LifeTime(hours)

# 1  Extended offline  Completed: read failure  90%  7482  24365031
# 2  Short offline     Completed: read failure  90%  7482  24365031
# 3  Short offline     Completed: read failure  90%  7482  24365031
# 4  Short offline     Completed without error  00%     0  -

So I presume a bad block/sector on the disk.
I had high hopes this article:
   https://www.freebsddiary.org/smart-fixing-bad-sector.php
would show the way, but it seems to quit right at the good stuff.

Can it be remapped, and if so, pointers to how?

Thanks,

Gary