At around 4pm yesterday we arrived at our first destination, Nihoa Island. Nihoa is a large basaltic rock with steep 900 foot cliffs and birds everywhere. It is believed that native Hawaiians inhabited this island between the years 1000 CE and 1700 CE. Over 80 archeological sites and heiaus (religious sites/temples) were discovered here and it is believed that about 175 people lived on Nihoa. We are unsure as to why the native Hawaiians left Nihoa, but we do know that their departure coincided with the arrival of westerners to Hawaii.
Today was our first day of diving ops. Diving off of the Hi’ialakai is a fun experience. The Hi’ialakai hosts several small dive boats that are lifted off the ship and into the water with a crane. The divers jump onto one of the small boats with their gear while it is resting against the side of the ship. The dive boat is then lowered into the water while the ship is still moving. It always amazes me how smoothly they drop us into the water given that we are still attached to a moving ship.
We got to do two dives this afternoon right along side the island. Both dives were used to get our protocols squared away for a water exchange experiment. Oscar is very interested in understanding how reef topography affects water exchange, specifically for crevices or holes in the reef. One way to quantify water exchange rates is by injecting a small amount of inert dye into a hole and then calculating how long it takes for that dye to dissipate.
Seems easy enough right? 🙂 For those of you who read my blog last year you all heard me complaining about the surge. This site was no different. The water was crystal clear and the deepest color blue I have ever seen, but it was also a washing machine making it a little bit of a challenge to stay in one spot and collect a water sample. Nevertheless, it was still an absolutely amazing dive. On our second dive we decided to go a bit deeper which was much less surgey and everything went really smoothly. Diving at Nihoa was a treat because not many of the cruises are able to come here. We are transiting all night to the next location and tomorrow we will wake-up at Necker!