2. The 20th kuhane station is Taharoa. Although the possible clue tahana from Metoro is not much to go on, we could perhaps read tahana as an allusion to Taharoa.

When sun is going down he is inclining his head (hakataha):

Taha. To lean; to go down (of the sun in the evening).  Taha-taha. 1. Side, edge; shore: taha-taha tai. 2. To move from side to side (of a boat), to swing. Vanaga.

1. To bend, sloping, to go hither and thither, to evade; ki taha, near; taha ke, to go in different directions; tahataha, frontier, horizon; hiriga tahataha, to cross, to go across; hakataha, to divert, to turn away, to go aside, to be on one side, to dodge, to shun, oblique, to incline the head, to turn over on another side, to avoid, to subject; mata hakataha, to consider; tae hakataha, immovable. 2. To tear. Tahatai (taha 1 - tai), littoral, coast, shore; tahatahatai, coast. Churchill.

As to the following -na, we could say that the boat of the sun has come close to the horizon in the west, close to us who live here (ná). Both sun and moon appear larger when they are close to the horizon.

Ná, here; ná ku-tomo-á te miro, the boat has arrived here. Vanaga.

1. When, as soon as (ga). Mgv.: na, because, seeing that, whereas. 2. The, that, some, any, certain (ga); pei na, thus, like that. P Mq.: na, the (plural). Ta.: na, id. 3. Of. P Pau.: na, of, belonging to. Mgv.: na, of, by, on account of. Mq.: na, of, by, for, on the part of.Ta.: na, of, by, for. 4. ? possessive; na mea, to belong to (? his thing). Mgv.: na, him, of him, to him. Ta.: na, he, his, him. 5. (ana 2); i muri oo na, to accompany. Churchill.

Quite interesting it is to find Taharoa described in Manuscript E as the place when the king stopped all movements by powerful incantations in order to bar the canoe of his sister queen Ava Rei Pua to come first to the shore of the island. I think it was a time of solstice (when sun stands still).

"He worked mana in the fishing grounds." It could refer to the winter solstice (where there should be fishes, in the middle of the 'water' season).

The following (21st) kuhane station is Hanga Hoonu, The Bay of Turtles, and the explorers found it full with fishes:

... Again they went on and reached Hanga Hoonu. They saw it, looked around, and gave the name 'Hanga Hoonu A Hau Maka'. On the same day, when they had reached the Bay of Turtles, they made camp and rested. They all saw the fish that were there, that were present in large numbers - Ah! Then they all went into the water, moved toward the shore, and threw the fish (with their hands) onto the dry land. There were great numbers (? ka-mea-ro) of fish. There were tutuhi, paparava, and tahe mata pukupuku. Those were the three kinds of fish ...

Tahana is not mentioned as one of the 3 kinds of fish, but tahana could depict a kind of fish.