Photo can be in better resolution taken with lower ISO-800 or less.
Found a similar problem while shooting at Crystal & Fantasy Caves in Bermuda. Had a pocket-sized Canon Power Shot 100-IS camera with a shutter that went up to 15s. Relied on display viewer for guide, found a few places to steady the camera including the steps and handrail on the stairs going into the cave since it was not practical to carry a tripod around. (As always, tried to protect the natural formations by not leaning the camera against them.) Had the hand on the shutter for a few extra seconds to take multiple shots so that you can get at least 1 of several being sharp.
With the camera at 8 mpix, found shots with camera set at ISO 80-100 with support worked best than at higher ISO 400 hand-held. In some cases the shutter speed went down to 1 - 4s and the shots came out nicely. Did not rely on the IS (stabilizer). Many pocket-sized cameras the IS is done by software enhancement you do see a sharper image but often a double one as well. When the shot is steady enough, the IS feature won't kick in.
