I prefer that my hose stays buried as much as possible. I tied rope to the four corners of my 'base' and brought them to a central knot. Then tied a pop bottle above that with its height designed to be just under the surface of 'average depth' so that it isn't visible. Some have purposely tied a duck decoy or other asthetically approved item that floats to mark the spot of the diffuser all the time.
Even if I have high water and can't see the float, I take a landscaper rake with me to the area where I think it is and can usually snag the rope at the knot and pull it straight up. I hang on to the rope over the side of the rowboat, clean the diffusers and let it go back down. The trick is getting it to set back down upright. I added a big plastic tote under my diffuser to try to get it off the bottom (less silt plume) and to try to keep it upright when I release it but I still often release and wonder if it is setting upright.
the other trick is to turn it on, then snag the rope in the plume. It seems easier to clean the diffuser membranes when they are blowing air but I feel like I have to be very careful (use gentle finger pressure only and no brushes)as to not make the tiny holes bigger or scratch the membrane when under pressure.
I have pulled mine up to clean them and even took them out one winter (plugged the end of the air line, attached weight and a line with buoy so I could find it next spring).
But the method I like best is to snorkel out with mask fins and snorkel to the bubble plume, dive down while holding my breath, and lightly scrub the surface with the cotton gloves I am wearing. Usually have to grab on to the diffuser to keep from floating to the surface. Sometimes takes two or three times because I can't hold my breath long enough to get it done in one dive. Have done it with SCUBA gear but that is overkill for a quick job.
Cleaning diffusers 
