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10

Yes. My wife is a geologist and has been on a couple of research cruises in the south Pacific and Indian oceans. It used to be quite common to have a "swim call" when the seas were calm. The vessel would stop, and the crew and scientific staff would go for a swim. In one case a student lost her leg to a shark during a swim call on a NOAA ship. I believe that ...


7

For practical purposes, rarity is beyond difficult to answer. Sure there may be a biological survey buried somewhere in some journal, but specific topics like that don't get much traction outside of small specialized communities of biologists. For a heuristic, I have used a combination of google images and pricing. For google images there are certainly ...


7

First things first you aren't going to be able to get longitude without an accurate clock and/or a tome of sight reduction tables. Without those aids which you'd be hard pressed to create while marooned on an island your navigational options are limited. The best you can really hope for is to follow a latitude line/plane. I think a cross staff would be an ...


6

The blue-ringed octopuses (genus Hapalochlaena) are three (or perhaps four) octopus species that live in tide pools and coral reefs in the Pacific and Indian Oceans, from Japan to Australia (mainly around southern New South Wales and South Australia, and northern Western Australia). They are recognized as some of the world's most dangerous marine animals. ...


5

First things first. You need a sailboat in order to sail. A raft isn't navigated. It drifts and is blown around. If you have a sailboat you already have the navigation tools you need or at least most of them. Any tools that you can make on an island with a pocket knife will be no better than just looking up and recognizing the stars. The level of accuracy ...


5

What your describing is flocking. It's an extremely complex behaviour where individuals react to their immediate neighbours giving the sense that the whole flock moves as a whole. Birds naturally flock (in the air or on the ground) as a defensive mechanism against predators, etc. Though complex there appears to be some basic rules to the mechanism as a ...


5

This is really just a hypothesis, but here in the UK we also get mixed wader flocks. A significant reason for large/mixed flocks to occur is predation. Watch out for what happens when a large flock of waders (almost by definition very exposed on the ground) spots a falcon. They scatter in every direction, not maintaining a straight line for any time at all. ...


4

If you aren't drifting, then one item that would be useful is a log. This is as simple as a chunk of wood and a line. Time how long it takes for the log to reach the end of the line. This gives you a consistent idea of your speed at least relative to the parcel of water you are in. A stone on a string acts as a pendulum. This gives you a pretty ...


3

You're right that the various species of shorebirds, including in your area, like most of the same types of foods. The diet is primarily comprised of invertebrates such as crustaceans, worms, mollusks, and insects. Although some species are indeed bigger, they tend to co-exist peacefully. One reason is that they have different types of bodies and bills, ...


3

In the UK one of the more dangerous sea creatures is the weever fish. They are often found in shallow, sandy water, particularly around Cornwall and the south west, and have venomous spines on their backs. Being stung is very painful and can result in severe swelling. Stings are generally caused by standing on them unawares while barefoot, so can easily be ...


3

After having a look on Google I found that yes you can use a pull buoy out in open water, and that they are often used in Triathlons to help the swimmer as they will often be very tired at this point and can allow their legs to rest between the bicycle stint and the running stint. This is as they are designed to improve your pull, leaving your legs to 'drag' ...


2

Disregarding floating devices altogether (because they can easily be abandoned if needed), where and when you decide to swim in tidal waters should entirely depend on expertise of those waters. Currents are local phenomenon which do not necessarily replicate themselves from one place to another because the number of variables that lead to a predictable ...


2

I think a reasonable guess would be jellyfish larvae, also known as "sea lice." Sea lice are actually the microscopic larvae of jellyfish and other ocean stingers which contain the same nematocysts (stinging cells) as mommy and daddy. (They) are probably the most commonly encountered stinging threat to divers and swimmers at the beach. There's a ...


1

"hanging out" together happens because different species eat the same food, require the same nesting areas, migrate in the same flyways, etc. Many species compete/become territorial for nesting areas, but less so for food sources.



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