HTTPS protects the website and the browser. Most websites only allow traffic over HTTPS, and many when attempted to be accessed over HTTP will 404 redirect the browser to HTTPS. This pilot odyssey site does not.
Insecure HTTP has several hackable vulnerabilities, some hacker can re-define global DNS of
http://www.pilotodyssey.com to their own web server, but they cant get around the certificate. Having certificate forces the browser to check the certificate against a trusted authority (Such as Comodo or Veri-Sign). A hacker can right out claim
http://www.pilotodyssey.com records as their own and just send you to a similar site where the hacker can do what they please with your information un-willingly. Some hacked (spoofed) sites even look exactly the same yet are compromising your browser/computer etc.
HTTPS also carries with it site and traffic encryption, where HTTP runs as plain text. Any packet sniffer can likely pull out keystrokes, text, pictures, names.... Even credit cards, passwords etc from HTTP whereas HTTPS uses levels of secure packet transfer as defined by the web server to keep things locked from view.
HTTPS uses tcp port 443, while HTTP uses tcp port 80. Port 80 as it is known to be insecure is basically wide open to hackers around the world as it is known to be un-encrypted; and creates an open hole for insecure sites - especially ones with old hardware/software, without additional firewalls protecting it from DDoS or brute force attacks etc. Sites running HTTP port 80 are the first to 'go' so to speak.
The long and short of it is, this site is in-secure; but what does that really mean?? Probably not much. There are no major personal or financial artifacts on this site. Now, if ebay.com or amazon.com or even nasdaq.com was insecure that would be a totally different nightmarish ballgame.