Absolutely agree, the Need to explore new routes was there after 1453 CE. But a sea route alternative would not have even been considered if there weren't already ships in Europe capable of doing the exploration and returning safely (well, relatively safely) - and those were already in development and use long before the Need came up when Constantinople went down. The Scandinavians in Drakar or Knorrs sailed across the Atlantic around 1000 CE to Canada, and may have explored clear down the American coast to the Yucatan (I say 'may' because this is based so far on a single fresco in a Mayan site that appears to show 'white men' and a clinker-built hull on a ship, but Mayan artistic conventions make any interpretation uncertain). The Carrack hull and multiple masts appears in Genoa in the early 14th century over 100 years before the Fall of Constantinople. Chinese and Indian/Southeast Asian sailors had a large and lucrative sea trade built up since at least the Song Dynasty (10th - 13th centuries) between China, India, Sri Lanka, Indonesia, the Philippines and across the open Indian Ocean to the east coast of Africa/Arabia. The problem for Europe, of course, was that all of this didn't get past Arabia/Egypt without going through a severe 'mark-up' by Islamic Middlemen before reaching Mediterranean entrepots.
So, again, any "Renaissance" was based on already-existing or in development technologies and techniques in Europe, the product of scientific and technical progress during the Medieval Era.
PS. There's a new book just published on Medieval Science: The Light Ages, which I just ordered earlier today, so I may be back in a couple of weeks with more examples of "Medieval Tech Tree" Developments!