Persons convicted of violating any of the provisions of this chapter, or the regulations adopted in accordance with this chapter, shall be punished by a term of imprisonment not exceeding one year or by a fine not exceeding five hundred dollars ($500), or both, for a first offense; and by a term of imprisonment not exceeding four (4) years or by a fine not exceeding two thousand dollars ($2,000), or both, for a subsequent offense. Any boat or vessel, or outboard motor, or dredge, tongs, rakes, or other implements, commonly employed in the taking of shellfish, seized from any person as used in violation of §§ 20-8.1-5 and/or 20-8.1-6, shall, upon conviction of that person, be forfeited to the state. That forfeiture shall follow the course provided in chapter 21 of Title 12 as amended and § 20-1-8.1.