Fremennik sea boots 3 are obtained by completing the easy, medium and hard Fremennik Province Tasks and speaking to Advisor Ghrim on Miscellania to claim the rewards. They can be reclaimed from him if lost. It provides the same stat bonuses as a pair of Adamant boots.
From Fremennik sea boots 1 and 2 Edit
Ability to remotely contact the Fossegrimen to recharge the Enchanted lyre, receiving one less charge than normal
Shark (and bass with ring of charos (a)) give 1 charge, manta rays give 2 charges, and sea turtles give 3 charges
Ability to teleport using the lyre without using a charge once per day (resets at 00:00 UTC)
At all times
Recharging the lyre in person gives two additional charges
Shark (and bass with ring of charos (a)) give 4 charge, manta rays give 5 charges, and sea turtles give 6 charges
Peer the Seer will act as a Bank Deposit Box
Improved rate of gaining approval on Miscellania and Etceteria
Fremennik sea boots 3 only Edit
At all times
Advisor Ghrim will buy flatpack furniture and put the money on the treasury used in Managing Miscellania. The amount received is equivalent to 10% of the store price for materials used for the flatpack.
Ability to change the lyre teleport to Waterbirth Island by speaking to Olaf the Bard
Fremennik citizens will use the Far-strider honorific