There a small group of Moken people await her arrival, as they do every weekend.
The Moken, or Sea Gypsies as they are commonly known, are semi-nomadic sea dwellers whose primary sources of income are fishing and gathering shells.
"Wasana stays at the Moken village every weekend, I usually help her ministry on Saturdays," Branding said.
Tasked with her own ministry among migrant factory workers in the seaside town of Ranong, Thailand, Branding believes it is vital to support believers in the pursuit of their calling.
"We may not have the same calling, but it is still important, as a believer, to help Wasana reach those she is called to share with," Branding said as she stacked packages.
Moonsiti slides her feet across the wobbly wooden plank to carry packages to dockworkers, who form an assembly line to help unload the cargo. Boxes filled with snacks, food, medical equipment and Bible stories are catalysts Moonsiti uses in sharing the Gospel among the Moken.
Today, Moonsiti taxis across the island, but normally she prefers to save money and walk, saying, "If I can walk, I save money to buy more things for the children."
Branding and Moonsiti use motorcycle taxis to zip over hills and through the tropical trees to a small beach on the southern end of the island. Dropping their bags at a hotel, they begin the final leg of the trip down the beach. The women pause to remove their shoes and roll up their pant legs.
Moonsiti's eyes sparkle and a smile tugs at her lips while she updates Branding on recent village events. Reaching the canal crossing, Moonsiti wades straight through, greeting the jumping, waving and swimming children awaiting her arrival.
Moonsiti is fortunate the tide is still low.
"If the big tide is in, it gets quite rough," Moonsiti said as water sloshed around her feet. "I cannot [go through] then, so I wait, sometimes two hours, [before crossing]."
A concerned father carries his son up to Moonsiti and asks for help as she walks through the village. The boy has badly burned his toe and it needs to be cleaned. Having worked in medical missions for 16 years, Moonsiti helps administer medicine to those in need.
She also helps educate Moken villagers on hygienic living on land. Accustomed to life on a boat, the Moken find tasks such as using toilets foreign.
"I teach them about hygiene and how to protect themselves against diseases by keeping the village clean," Moonsiti said. "I teach them what to eat [on land], like growing vegetables and raising chickens."
After the boy's foot is bandaged, children with sun-streaked hair clamor into the peach-painted church and wait for the day's lesson.
Moonsiti says it was not easy starting to teach the Bible here, but God has begun working in this village.
"At first, I started with Genesis, 'In the beginning, God created the world...' and keep [storying] like that. They love it -- stories like Noah's Ark," she said smiling broadly. "Because Sea Gypsies live on the ocean, they can see the story [come to life]."
At the end of the lesson, kids line up to repeat the Bible story back to Moonsiti. Their attentiveness rewarded with sweet treats, the children rip into their colorful packages and playfully run.
Rays of sunlight stretch farther and farther. The buzz of fishing boats grows louder as fishermen come in with the tide. The boats will stay at shore until the tide begins to drift out again.
Moonsiti shares her heart for the Moken people as she packs up for the day.
"I pray for Jesus to come into their lives and [let them] know that we have hope in Him," she said.
Branding helps lock up their supplies for the next day, and an entourage of children guides them to the shore for the long walk to the hotel. Because the tide is in, the women are pulled across the swollen canal on a small foam and plywood raft attached to a rope.
Tomorrow they will come again, telling more about the Bible and God's love for the Sea Gypsies of the Andaman Sea.