Advice on using a Wide Angle Lens

I've been doing Underwater photos for about 6 months now using a Canon A710IS with the Ike housing and Single Strobe, mostly in the Macro mode. I am geting pretty comfortable with this but now I am Off to Honduras next week where I am sure I will want to shoot many Wide Angle shots. I really have not used my Ike WAL before and need to know if there are any little hints/tips I should know about? Or are there any MAJOR tips I need to know? Can I still shoot close-ups and macros when the WAL is on? I understand that it affects my closeup focal length but thats about all I think I understand. Because the IKE WAL is a screw on, rather than a bayonnet type, I would rather not be putting it on and off U/W.
Appreciate all input. DD

Everything will look smaller with your WA lens on. Depending on the lens, your minimum focus distance might change. Get in the swimming pool and see how close you can get and still focus. One of the advantages of a wide angle lens is being able to shoot closer to large creatures and still fit them in the picture. A picture of a large sea lion, shark or turtle with a wide background of reef, kelp, etc. becomes possible. One key is if you have a subject, other than the reef or the wide view to the sunny surface, keep it close to the camera. Fill most of the frame with your subject, but have a pleasing background of surface ripples, sunball, reef etc. Depending on your camera, housing, WA lens combo, you might have to zoom the camera a tiny bit to keep from vignetting slightly. When you do your pool test, check your shots on the computer for dark corners. If you have them, try tapping the zoom lever just a touch and they'll go away. You won't get as wide a shot, but you won't have to crop it afterward. Also, since a wide angle lens takes in more area, it can take in more light. Check your f-stop settings in the pool to see how they compare with your shots without the lens. Remember too, that your strobe will only cover the close foreground of your shot. Try shooting wide shots without the flash, using manual white balance, to avoid backscatter. You can take macro shots with the WA lens on if the minimum focal distance is close enough, but they tend to look kind of flat. I usually put my WA lens on at the beginning of the dive and unscrew it and put it in my BC pocket when I'm looking for small stuff. If you drop with your lens on the camera, make sure you rotate the camera around enough to get all the bubbles out from between the port and the lens. Don't over-tighten your lens. I've had a couple of instances when I went to take the lens off and the port started to unscrew instead...scary! Just turn it on gently till it stops. I've never had the lens loosen during a dive.
Where in Honduras are you going? We're doing Utila in June, soon as school's out. Can't wait.

Thanks, Larry.
I am leaving this coming Saturday for LBR on Utila. First trip to Honduras and I am hoping I will need the WAL to shoot some Whale Sharks.
Won't have time to play in the pool with the camera before I leave, but when I got the complete rig 7 months ago, I practiced with the WAL on land, so I have an idea as to how close I can shoot Macros.
I forgot about the Vignetting problem & the possibility of needing to adjust F-stop. I will certainly keep that in mind as well as your composition tips. Generally I ALWAYS try to have a person in the frame, unless it's a true Macro shot.
When I get back I'll PM you with a report on the trip-Where are you staying on Utila? DD

We're staying at Deep Blue Utila. Hope there are still some Whale Sharks hanging around by mid June.

PS What did you do about shots? That's some pretty scary stuff they recommend.