His own advisors prohibited him from visiting Ulimo Base.
It was too risky to dispatch Ves on such a high-risk mission. His status and importance to the Larkinson Clan was far too great to allow him to visit a formidable pirate fortress while he was heavily outnumbered and outgunned.
Once the Dry Snakes discovered that the infamous pirate killer sneaked into their own home, They would certainly lock down Ulimo and seek to kill or capture Ves at all cost!
The entire point of dispatching a small force of Larkinsons disguised as pirates was to limit the losses in the event of a disaster.
If the Dry Snakes and its vassals managed to identify and eliminate the Larkinsons, then the Larkinson Clan and the task force wouldn't actually suffer that much losses!