Kei te whiwhi ngā waka pūnaha riro i ngā paihere āhuarangi i te kawe i ngā wai, nō te mea he mīhini te mohiotanga me te huarahi pai ki te whakatupu i te whakamahere. Ko ngā pūnaha iti-kore pēnei i te HDPE (high-density polyethylene) kei te whakamahi tonu hei hanga i ngā pūnaha, tēnā ka tiakina i ngā momo rongoā e mōhiotia ana hei whakapae i te mōhio ki ngā momo rongoā e riro ana i te whakamahere. Nō reira, ka noho ngā waka nei hei kawe i ngā wai kai-taumata me etahi rongoā, hei whakamahere i te kawe i ngā wai me etahi atu rongoā. He mea iti-kore ake hoki te utu o ngā waka pūnaha riro i runga i ngā pūnaha matua, me te iti noa iho i ngā mahi whakatatari. Ki te whakapae, ko tā rātau nui rawa atu he whakatupu me te paihere ki ngā momo wai e rite ana, ka mutu, ka kitea he whakaaro pai rawa te kawe i ngā wai i roto i ngā whenua e hiahia ana ki te whakamahi me te utu iti.