While everyone was still marveling over the fact that Rowan had decided to use a boat to get across the lake, Rowan is shivering from the spray of icy lake waters that is being thrown into her face by a bitter chilly wind. Unable to properly cover her face, she can only pull up her coat even further up to her chin and snuggle down into her fur-lined coat to at least protect half of her face up to her nose. She knew she had forgotten something else this morning, when she ran out of the dorm room, a warm fur-lined cap and a scarf. And gloves, but at least her left hand was nice and warm in her coat pocket.
A fierce shiver ran up Rowan's spine despite having taken the Pepperup Potion, which was still in her system to keep her warm. But the climate circumstances were a bit extreme and the Pepperup potion could only do so much. It was a simple potion not a bloody miracle worker.
Rowan let out a rather ferocious sneeze but could only wipe her runny nose on her coat sleeve in utter disgust. She really should carry a handkerchief on hand, but she was so used to Terry or the girls having a clean on hand that she never really bothered to carry one. It was a good memo to make a pointed note of at least.
Rowan's right hand was already turning pale blueish just from the wind and spray of the lake. The cold was causing her fingers to ache, but she couldn't cast a warming charm on them given her present state of health. Ignoring the fact that she still felt ill and rather weak at the moment, what she was presently doing was costing her quite a bit of energy. She'd need to conserve every single bit of energy if she wanted to succeed in her task. The only silver lining to the entire situation is that her ears are being kept warm thanks to the puffs of steam still coming out of her ears.
Using her wand, Rowan steers the boat across the icy lake waters in the direction she wanted. She had for one insane moment briefly considered swimming in the icy lake using the gifted bracelet from Dumbledore, before outright putting that ridiculous idea out of mind. If Potter couldn't win in that manner, and he had his outrageous Gryffindor luck to boot to aid him, there was no chance in hell she'd be able to surpass him. More than likely, she'd run afoul via the Grindylow's and she wasn't about to repeat Fleur's traumatic experience.
Nor did she at present speak enough Mermish to garner the aid of the Merpeople. Excluding the fact that they very likely couldn't aid her in completing the task, she didn't speak very much Mermish at the moment. She could say basic things like colors, or this is tasty, but those are beginner phrases. More than likely she'd end up insulting the entire merpeople population in the lake, and forever be banned from approaching the lake.
Shivering at the mere thought, Rowan moves her wand slightly to the left to keep on course. Resting her wand-held hand on her lap, she returns to her thoughts. Another option she had briefly considered was creating an ice path across the lake and skating over it toward the hostage's location. But the problem with that scenario was the sheer amount of magic it would take to create and maintain said icy path without taking into consideration the effects of nature itself.
Ice is easy to traverse when it is dry, but not when there is icy water pouring onto it in waves. And excluding the fact that a thin strip of ice would probably break from the pressure of the lake's waves if she skated across said ice, there were liable to be melted patches causing her to slip and fall. Therefore, causing her to fall onto the ice or the ice-frozen lake waters. Either way, neither scenario would have boded well for her.
Another solution was the Summoning charm, (Accio). However, there was just one problem with that conjecture, magic spells did not tend to work very well underwater. Potter had proven that before when he attempted to rid himself of the Grindylow's. And though it was successful but only because of the spells' side-effects.
Rowan abruptly held out her wand to halt the boat. Holding out her wand, she closes her eyes and opens her mind mapscape. Carefully keeping her eyes closed and focused on the dot down below, she says, "Carpe Retractum!" She'd have kept her eyes open, but the charm itself required the target to be in the caster's sight, which was only possible via her mind mapscape.
From the tip of her wand, a glowing orange-like rope emerged like a snake before darting into the dark icy waters down below. It seemed like an eternity, but it was only minutes really when the rope found its objective. The glowing orange snakelike rope wraps itself around its quarry, before coming to a stop.
Unable to open her eyes as it would cancel the spell, Rowan grunts and leans back into the boat setting her feet firmly under the boards, before pointing her wand in the direction she needed. The boat slowly turns around, before surging forward across the water. The boat is suddenly pulled back for a moment by the weight and tug of the anchor, before heaving slowly forward inch by inch.
Rowan lets out a breath she was holding but keeps a firm grip on her wand and her feet tucked under the boards. The instant she realized the spell would backfire and drag her into the water towards the object of her choice, rather than the object back to her.
Down below, slowly but surely the wooden post that held the sleeping figure of Barrett Boone slowly is pried loose from the muddy grounds. Suddenly, with a firm pull from above the wooden post became loose, before being dragged much faster through the water.