# Lock 21 Dive Site, United States: what it is and when to go > Lock 21 Dive Site is a dive site in United States. Interests: Diving. The best time to visit is June to September. In June there are 15 h 24 of daylight, and in December, 8 h 36. Here is what it is, where it lies, when to come, how to get there and what else is nearby to turn it into a trip. - Address: https://kokai.app/en/paises/america/estados-unidos/lock-21-dive-site/ - Reviewed on: 2026-10-08 - Language: en ## In a nutshell - **What it is:** Dive site · Diving - **Where:** United States - **Best time:** June to September. - **Nearest airport:** EWR Newark, 483 km as the crow flies - **Website:** [waymarking.com](https://www.waymarking.com/waymarks/WM83Y_LOCK_21_St_Lawrence_river) - **Coordinates:** 44.9975, -74.89931 ## What it is and where Lock 21 Dive Site is a dive site in United States. Its coordinates are 44.9975, -74.89931; the nearest main airport is Newark Liberty International Airport (EWR, Newark), 483 km as the crow flies. How to get around United States (train, car, bus) is covered in [its country guide](https://kokai.app/en/paises/america/estados-unidos/#moverse). - [Where it is](https://www.google.com/maps/search/?api=1&query=44.997495%2C-74.899309) - [Directions](https://www.google.com/maps/dir/?api=1&destination=44.997495%2C-74.899309) It is one of the [Diving](https://kokai.app/en/paises/america/estados-unidos/submarinismo/) places in United States. In [Kokai](https://kokai.app/en/) it is already on your trip map next to the places you save yourself, and it goes into a day's plan with one tap. ## When to go The best time to visit Lock 21 Dive Site is **June to September**. | Mes | Época | Hours of daylight | | --- | --- | --- | | January | Better not | 8 h 57 | | February | Better not | 10 h 11 | | March | Better not | 11 h 37 | | April | Possible | 13 h 16 | | May | Possible | 14 h 39 | | June | Best time | 15 h 24 | | July | Best time | 15 h 06 | | August | Best time | 13 h 54 | | September | Best time | 12 h 18 | | October | Possible | 10 h 42 | | November | Better not | 9 h 18 | | December | Better not | 8 h 36 | In June there are 15 h 24 of daylight, and in December, 8 h 36. Daylight hours are calculated from the site's latitude for the 15th of each month; when planning a full day on foot they matter as much as the weather. When to go to United States in general, with its festivals and peak seasons, is in [its country guide](https://kokai.app/en/paises/america/estados-unidos/#cuando-ir). ## Before you go to United States To enter United States there are 9 things to sort out before you leave, starting with “Book national parks and cars in advance”: they are all, with their deadlines, in [the United States checklist](https://kokai.app/en/paises/america/estados-unidos/#antes-de-salir). Currency: US dollar (USD); plugs: Type A and B · 120 V · 60 Hz (you need an adapter, and check your devices' voltage); emergencies: 911 for everything. In [Kokai](https://kokai.app/en/) you tick off the checklist inside your trip, and each item reminds you when it is time to do it. ## What is nearby - [Robert Moses State Park – Thousand Islands](https://kokai.app/en/paises/america/estados-unidos/robert-moses-state-park-thousand-islands/): State park in St. Lawrence County, New York · 6.4 km - [Croil Island](https://kokai.app/en/paises/america/estados-unidos/croil-island-state-park/): Island in the St. Lawrence River in St. Lawrence County, New York, United States · 6.6 km - [Seaway International Bridge](https://kokai.app/en/paises/america/estados-unidos/seaway-international-bridge/): Bridge over the St. Lawrence River between Canada and the United States · 13 km - [Upper Canada Village](https://kokai.app/en/paises/america/estados-unidos/upper-canada-village/): Living museum in Ontario, Canada · 14 km - [Prehistoric World](https://kokai.app/en/paises/america/estados-unidos/prehistoric-world/): With kids · 17 km Distances are as the crow flies. Everything else is in [the United States guide](https://kokai.app/en/paises/america/estados-unidos/). ## More in United States: Diving - [USS Yorktown](https://kokai.app/en/paises/america/estados-unidos/uss-yorktown/): 1936 Yorktown-class aircraft carrier - [USS Arizona](https://kokai.app/en/paises/america/estados-unidos/uss-arizona/): 1915 Pennsylvania-class battleship - [Japanese aircraft carrier Akagi](https://kokai.app/en/paises/america/estados-unidos/akagi/): 1925 aircraft carrier initially laid down as a battlecruiser - [Dry Tortugas National Park](https://kokai.app/en/paises/america/estados-unidos/parque-nacional-tortugas-secas/): 64,657 acres in Florida (US) managed by the National Park Service - [Japanese aircraft carrier Sōryū](https://kokai.app/en/paises/america/estados-unidos/soryu/): 1935 Sōryū-class aircraft carrier - [Japanese aircraft carrier Kaga](https://kokai.app/en/paises/america/estados-unidos/kaga/): 1921 Tosa-class battleship Every United States place under Diving, each with its season, is on [its page](https://kokai.app/en/paises/america/estados-unidos/submarinismo/). ## Frequently asked questions ### What is Lock 21 Dive Site? It is a dive site in United States. ### When is the best time to visit Lock 21 Dive Site? June to September. In June there are 15 h 24 of daylight, and in December, 8 h 36. ### How do you get to Lock 21 Dive Site? The nearest main airport is Newark Liberty International Airport (EWR), 483 km as the crow flies. From there, [directions](https://www.google.com/maps/dir/?api=1&destination=44.997495%2C-74.899309) opens the route on the map, and how to get around United States is explained in [its country guide](https://kokai.app/en/paises/america/estados-unidos/#moverse). ### How do I add it to my trip? With one tap. In Kokai it is already on the United States map, next to the places you save yourself: add it to a day's plan, give it a time and, if you like, get a reminder when you pass nearby. ### What else is around here? Nearby you have [Robert Moses State Park – Thousand Islands](https://kokai.app/en/paises/america/estados-unidos/robert-moses-state-park-thousand-islands/), [Croil Island](https://kokai.app/en/paises/america/estados-unidos/croil-island-state-park/), [Seaway International Bridge](https://kokai.app/en/paises/america/estados-unidos/seaway-international-bridge/). The rest is in [the United States guide](https://kokai.app/en/paises/america/estados-unidos/). Data from [OpenStreetMap](https://www.openstreetmap.org/node/663869512), licensed under the ODbL, and from [Wikidata](https://www.wikidata.org/), CC0. Daylight hours are calculated from the latitude. More in [credits](https://kokai.app/en/aviso/#creditos).