Take a look at this map. The maroon/burgundy spot is the Kingdom of Cusco, which was the precursor state to the Inca Empire. It's not very close to the coast (especially when you consider how mountainous the terrain around it is), or even very close to Lake Titicaca, where indigenous Andeans developed their own remarkable shipbuilding traditions. As a rule, the rivers that flow through the area (and most of the Andes) are too treacherous for navigation. All of these factors sit behind the reality that early Inca society developed without any serious seafaring or shipbuilding traditions.

When discussing Inca seafaring, it's important to hold that landlocked history in mind when we add in another factor: time. The Inca Empire existed for only a little longer than a single human lifetime; from 1438-1533 (and the earlier years of this time didn't include coastal possessions). The Inca had seen incredible success with their terrestrial armies, and had plenty of land left to work with. Without a seafaring history and with little need to begin one, it seems that even in its later stages, the Inca government didn't push for major seafaring practices.

However, this does not mean that coastal activities were completely absent from or unimportant to the Inca state. The coast of Western South America is incredibly rich in marine resources, and dozens of coastal civilizations which thrived there made use of fishing and seafaring technologies. Seafaring along the ancient Peruvian coast may actually have been uniquely important in the entire world as a fundamental step towards urbanized civilizations.^(1) Societies on the northern Peruvian and Ecuadorian coasts are especially well recognized for maritime traditions, and societies such as the Chimu (who would eventually be conquered by the Inca) depended upon seafood so much that certain shellfish are "ubiquitous" in Chimu archaeological sites.^(2) Nor was maritime activity limited to fishing; sea-based trade routes operating on balsa rafts existed in northwestern South America,^(3) and ships from this region probably made it all the way to West Mexico^(4).

These established maritime traditions did not end when the Inca conquered most of South America's western coast. Coastal peoples continued fishing for sustenance. And perhaps most importantly for this conversation, the Inca were now able to directly incorporate coastal trade into routes that led back to the imperial capital of Cusco. This is clearest in the Inca civilization's relationship with the Chincha civilization, which the Inca gained power over in the late 1400s. The Chincha "submitted to Inca power relatively peacefully and came to enjoy prominence among coastal provinces"^(5) It seems that the formerly independent Chincha rulers had a special relationship with the Inca, and this may have been due to their maritime capabilities. I'll pull a telling quote from an article:

Pedro Pizarro...noted in his memoirs that the Lord of Chincha was the only person beside the Inca himself allowed to be carried on a litter in the Inca's presence. Asked why this was so, Atahuallpa explained that the Chincha ruler was once the greatest lord of the coast and had "one hundred thousand rafts on the sea." Although this number is undoubtedly an exaggeration, Pizarro's account indicates the close relationship between Cuzco and Chincha as well as the latter's maritime significance. ^(6)

In its analysis of Inca-Chincha relations, the article then goes to conclude:

We suggest that the Chincha lord negotiated with the Inca for both a privileged position and the northern trading franchise in exchange for voluntary subjugation and payment of tribute. With their large number of fishermen, Chincha had experience with the sea. The Aviso states specifically that the fishermen would go out on their "balsas" or rafts almost every day (Rostworowski 1970:170)...[the Chincha acted as] state-sponsored maritime agents...Chincha is also well situated to be the transshipment point from southbound rafts to southeast-heading caravans. The Aviso states that some of the "merchants" "went with their purchases and sales from Chincha to Cuzco all through Collao" (Rostworowski 1970:171)...So long as the object of Chincha long-distance exchange was to provide Spondylus and other goods for the Inca, Chincha was the ideal agent.

So maritime trade was probably important to the Inca as a source of certain goods. Even if the ethnic Quechua or Inca ruling class wasn't directly involved in seafaring, it ensured the continuation of its subjects' maritime activities.

Finally, I'm going to reply to my own comment with one extremely tentative example of true Inca seafaring: the possible voyages of Tupac Inca Yupanqui. I wrote about the topic in a previous question, so I'm just going to copy and paste the relevant part below.

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^(1) Beresford-Jones, D., Pullen, A., Chauca, G. et al. Refining the Maritime Foundations of Andean Civilization: How Plant Fiber Technology Drove Social Complexity During the Preceramic Period. J Archaeol Method Theory 25, 393–425 (2018).

^(2) Turner B.L., Klaus H.D. (2020) Pre-Hispanic North Coast Cultures and Foodways. In: Diet, Nutrition, and Foodways on the North Coast of Peru. Bioarchaeology and Social Theory. Springer, Cham.

^(3) Hirth, K., & Pillsbury, J. (2013). Redistribution and Markets in Andean South America. Current Anthropology, 54(5), 642-647.

^(4)Callaghan, Richard T. "Prehistoric trade between Ecuador and West Mexico: a computer simulation of coastal voyages." Antiquity, vol. 77, no. 298, 2003, p. 796+.

^(5) Hill, K. B. (2020). Inca strategies of conquest and control: Toward a comprehensive model of pre-modern imperial administration on the south-central coast of peru (Order No. 28095680). Available from ProQuest Dissertations & Theses Global.

^(6) Daniel H. Sandweiss & David A. Reid (2016) Negotiated Subjugation: Maritime Trade and the Incorporation of Chincha Into the Inca Empire, The Journal of Island and Coastal Archaeology, 11:3, 311-325