Just noticed this post by me was 4 years ago now and nothing's changed.
Here.. www.seabreeze.com.au/forums/Stand-Up-Paddle/SUP/How-I-tape-my-paddles/
Yesterday I was lucky to meet two beautiful ladies paddling their brand new 10'6" Naish boards and the shop had fitted paddle guards for them.. One had fallen off and was lost already (after 10 minutes).. When I looked at the other it just pealed off effortlessly and would have been gone in minutes for sure.. What a waste.. If you are going to use it you need to stick it on real good but it's not needed and effects the way the paddles works.. Splashing going in and lifting water coming out.. These thin blades should be able to slip in and out without making a splash.. Even pulling through the water they have a negative effect.. It only took me a few minutes and I taped both of their paddles for them using electrical tape.
I think they (paddle guards) are only any good for demo boards and rentals /schools etc.
DJ
Although I admit to not having been out a lot lately, the tape I put on has been on for a few months now, so will continue to keep taping every few months - cheap & it saves the rails (it's actually cleaned the old black marks off the rails too!)
I have thin rubber blade guard and would not know it was there. It saves the board
and maybe yourself. Glue it on and enjoy