You could install a zinc strip near the ridge on the mossy side(s) of the roof. They work well and prevent future growth.
Interesting. I've never heard of this 30 Seconds stuff but it sounds promising.
I thought I'd bump this post. I know some guys tend to think of underwater cameras as an unnecessary novelty, but I got a great deal on the Micro Revolution Pro before the ice season and I have to say, I really like it. The camera reel system that Bob mentioned is really slick - basically wind it up like you're reeling in a fish and never have to worry about 30 feet of cord laying all over the place. The system I got also lets me record, which is a fun because I can show the video to my kids or parents and "share" my trip with them a little bit (and actually have proof I was on fish). But most importantly I like to know for certain what sort of structure I'm sitting on, and/or get my lure at the exact depth I want it.
I know if you're pretty familiar with the settings on your flasher you can be pretty confident if you're on rocks, mud or weeds - but I'd venture most people just aren't that dialed in with their flashers - I know I'm not.
Also, the quality of the cameras has come a long way. My first experience with an underwater camera was with the old school aqua view where you sort of looked down a tube at the monitor. Then about 10 years ago my friend had one that kind of looked like a small TV. Those were OK, but the fish had to be pretty close to the camera. The quality of the newer styles is far superior (I realize the water quality is a huge factor, but still, camera resolution has come a long way). The cameras are also a lot smaller and seem to bother the fish less.
Anyway, seeing as the hard water season is winding down I was just thinking that the camera I have is one of the more handy tools I have now. I don't keep it down for long, but it's great for getting set-up and or drop down the hole a few times to keep things interesting.
I wouldn't say I am anti-spearing but am not pro-spearing either.
Along with the ramifications on the fishery that has already been covered, nothing irks me more that all the unmarked spear holes and ice chunks left on top of the ice. I would rather see garbage left on the ice that a block of ice or a skimmed over unmarked hole. At least the garbage isn't dangerous to others.
I lived on Lake Osakis last winter and spent more than a few hours marking other peoples skimmed over spear holes. It is reckless and extremely dangerous.