You will cost at least 3 hours from Lo Wu to Zhu Hai.
You can also take bus from Lok Ma Chau/Huang Gang to Zhu Hai.
But the bus fare is the same to the ferry and take ferry from She kou to Zhu Hai only cost you 1 hour.
You can take bus B2/B2P to Shenzhen Bay Port from Tin Shui Wai Station or B3/B3X from Tuen Mun.