Bike then Swim! Is this alright?

Sounds like a great idea.  It won't hurt you unless you drown (no different than any other swim in the sea, that is). 

P.S.  Please, don't drown. 

Don't worry, I will not drown. My wife is already by the beach (drove her car hehehe) ready to rescue me. I am just a bit worried since I somewhat changing the order i.e. instead of swimming then biking I am doing the exact opposite. Ther should be reasons why Triathlon is order to swim-bike-run, hope just the norm of it nothing about 'health'! I have this thought that if your body is stressed out from biking... maybe getting immediately into the water could damage my veins/muscle etc. ... well I did it first time this morning though. I feel ok. Hope it would really be ok. Thanks Johnnykay, though. Fyi, I am a total beginner, never have the chance yet to join any Triathlon here in our place. I am eyeing at least the Sprint.

I think you worry too much dude.. working out is working out. I bike 15km to my pool most mornings.

I bike to the river, but it's only about 20 mins and then swim another 20 mins and bike home again.  Never had any problems healthwise and unless you've suddenly taken this up at 80, can't see why you would either.  The Scandanavians (sp?) do that sauna/snow thing and seem to think it's extremly healthy to go from all dilated veins to screaming cold in an instant.  

The swim/bike/run is so that you do the potentially most dangerous part when your freshest I suppose.  Have fun.

Theoretically, you could experience some cramping issues post-ride that you wouldn't otherwise. But other than that...I love swimming after I get off the bike, or when I finish a run.

As others have said, be careful and don't panic if you get a cramp.  I often follow up run with a swim and find new muscles cramps arise depending on how hard the run was.  Be sure you are adequately hydrated prior to jumpng in. Maybe a good strecth before taking the plunge.  Have a blast! 

Did it this morning....put in an hour's worth of biking, threw on the wetsuit, then eased into the water. My buddy warned me to acclimate well before going into a swim....body feels great in the water once you get a little water between you and the wetsuit, but the cold splash on your face is definitely shocking. Almost felt myself go vasovagal, but quickly adapted. After that, it felt great to be in the water. Since it was my first ows ever, i kept myself close to shore, where i could stand up at any point. The other thing is that you can take advantage of the buoyancy of the suit and float if you're tired. Just turn belly-up. lie still, keep your head up, and you float right up to the surface of the water with no effort from you. Really good tip my buddy gave me. have fun!

The only issues that I would foresee would be exhaustion or dehydration.  If you are totally wiped out at the end of the bike, getting in the water could be bad.  But it looks like you are planning a (relatively) short ride.  As long as you don't kill yourself getting there (literally and figuratively), stay topped off in terms of water (and depending on the heat/humidity, electrolytes), there shouldn't be a problem with swimming in general.  Just follow the usual precautions of swimming in the open water.

I really like doing a swim WO after running or biking as the swimming streches compressed muscles.  Just make sure to drink frequently since you may already be a little dehydrated. Also the cool water can sometimes cause cramping.  I have major cramping issues so I just try and kick as little as possible.