Another way to use your reel and SMB if you are ever left behind by a dive boat is to tie the line to your weight belt and drop the belt so it acts as an anchor. The first place they will come to when they start the search is your last known position and expand the search out from that point. .
The only problem I see with that is that the line on spool attached to the DSMB is very thin. If some current picks up at the surface it could be hard to stay with your DSMB and you could get separated from it.
I have a couple of tips, none I was smart enough to think of myself.
One was using water-soluble lube (like OB lube or KY jelly) on wrist and neck seals to make donning / doffing a drysuit easier. I hated talc for that, it gets everywhere. And diluted baby shampoo works too, but I don't like the smell of it, frankly. Just plain old lube works great. Of course I was a bit embarrassed when my Amazon shipment of 6 jumbo sized tubes of lube went missing and I had to chat with an Amazon CSR about it. (They re-shipped). Of all the thousands of things I ordered on Amazon, it had to be THAT one that went missing in transit...
When deploying DSMB if you are wearing thick gloves and/or have cold hands, use your bolt snap to grab the bungee holding the DSMB rolled up and pull it off. A friend reached over and did that for me on a very cold dive where we needed to get the marker up and I was fumbling with it. Now I do it every time.
Bungee mount and straps for computer - I LOVE these. Several tips here. First, you can make the bungee long enough that it's easy to get on and off your wrist, but then you can pull some of the extra bungee over to the other side of the computer when you are wearing it, so it fits more tightly. Also works great when you use a drysuit sometimes and a wetsuit sometimes. You can use one continuous loop, but tie a knot in one side, so if it ever gets cut, you don't lose the computer. And finally, I threaded my bungee through a line cutter. I wear one on each wrist and they are very handy. Cut some line off my buddy the other day before he even realized he was tangled.
DSS made the bungee mounts I have on some backup computers and my compass. He is out of businees, but I think you can still find bungee mounts from other manufacturers if you have a computer that has a wrist strap. Nice thing about the Perdix is it has holes built in.
Here's a pic of my computer with the line cutter on it. Right above the dive flag on the label, is where I have a knot tied - you can see that if either side of the bungee gets cut, that knot will keep it on my wrist. Sorry Flickr changed their options and I can't figure out how to embed photos anymore.
And for cutting harness webbing, this tip is genius. I never could get a very nice cut edge. Mine always was thick and re-frayed and I found myself burning it again and again. Follow this video from start to finish and you get a nice flat edge that is holding up really well. (Basically cut rounded edge with sharp scissors, burn but then immediately pound flat with a hammer (no more thick edge!) and when you are certain you are done with the burning process, superglue the crap out of it and it will hold up really well. You can't burn it after you glue it though.
Oh and a final one - dielectric grease on the threads on my camera tray to prevent it from seizing. Just soaking in fresh water isn't enough if you leave the camera mounted on the tray all the time. Found that out the hard way with my Go Pro.