07-23-2003, 05:50 AM
Hi-
I found this site for fishing. I am the only ocean float tube user in Okinawa Japan; many people call me crazy for using small inflatable in the ocean. I think if you have good knowledge of waters and creatures, you can be safe with what ever you have to do. I have read much information here already for hours today. I am also a surfer, kayaker, diver for many years and have some formal marine biology studies/computer science studies. I find this post most interesting because it combines my loves. This picture makes me scared first, but then I realize this is not a Chondrichthyes(shark), Carcharodon carcharias, or Great White Shark after I resize and sharpen the picture.
It’s a Cetacean (Dolphin), Tursiops truncatus, or common English name is "bottle nose".
These are reasons for conclusion. [ol] [li]Dolphins have dorsal fin shape like /( and Great white Shark have first dorsal fin like /|. [li]Great white shark does not surf; Bottlenose loves to surf and is often surfing with surfers or surfing bow waves from boats. Dolphins have fluke (tail fin) that gives positive buoyancy because of vertical forces are from horizontal fluke, shark has claudial fin (tail fin) that only gives horizontal forces. If dolphin surfs it can keep balance because of vertical fluke force, but shark can't keep balance because it only had horizontal claudial force or simply it does not have the correct hydrodynamics for surfing. [li]The dorsal fin of Dolphin is almost centered making head and tail look similar in length, The dorsal fin of shark is more forward and makes it have longer looking tail. [li]Sharks have a second dorsal fin between the main dorsal and claudial and on the bottom of the shark they have pelvic and anal fins, these are missing in this picture. Great Whites have larger claudial fin then dorsal. [li]Great White is easy to see because of gray top half and white bottom half with a distinct line. [li]Sharks Pectoral fin is very near under the first dorsal fin. Dolphins have flipper far forward and under compared to dorsal. [li][/semi-serious] the surfer is pointed in direction of the dolphin, if it was shark, he would be swimming in opposite direction back to safe beach.[/li][/ol]
If you surf or play in ocean for long time you will learn how to find if shark is near. I enjoy when dolphins surf in Okinawa, it scare all tourist surfer away so I have all waves for me
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I found this site for fishing. I am the only ocean float tube user in Okinawa Japan; many people call me crazy for using small inflatable in the ocean. I think if you have good knowledge of waters and creatures, you can be safe with what ever you have to do. I have read much information here already for hours today. I am also a surfer, kayaker, diver for many years and have some formal marine biology studies/computer science studies. I find this post most interesting because it combines my loves. This picture makes me scared first, but then I realize this is not a Chondrichthyes(shark), Carcharodon carcharias, or Great White Shark after I resize and sharpen the picture.
It’s a Cetacean (Dolphin), Tursiops truncatus, or common English name is "bottle nose".
These are reasons for conclusion. [ol] [li]Dolphins have dorsal fin shape like /( and Great white Shark have first dorsal fin like /|. [li]Great white shark does not surf; Bottlenose loves to surf and is often surfing with surfers or surfing bow waves from boats. Dolphins have fluke (tail fin) that gives positive buoyancy because of vertical forces are from horizontal fluke, shark has claudial fin (tail fin) that only gives horizontal forces. If dolphin surfs it can keep balance because of vertical fluke force, but shark can't keep balance because it only had horizontal claudial force or simply it does not have the correct hydrodynamics for surfing. [li]The dorsal fin of Dolphin is almost centered making head and tail look similar in length, The dorsal fin of shark is more forward and makes it have longer looking tail. [li]Sharks have a second dorsal fin between the main dorsal and claudial and on the bottom of the shark they have pelvic and anal fins, these are missing in this picture. Great Whites have larger claudial fin then dorsal. [li]Great White is easy to see because of gray top half and white bottom half with a distinct line. [li]Sharks Pectoral fin is very near under the first dorsal fin. Dolphins have flipper far forward and under compared to dorsal. [li][/semi-serious] the surfer is pointed in direction of the dolphin, if it was shark, he would be swimming in opposite direction back to safe beach.[/li][/ol]
If you surf or play in ocean for long time you will learn how to find if shark is near. I enjoy when dolphins surf in Okinawa, it scare all tourist surfer away so I have all waves for me![
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