I just took my monofins out for the second time ever today for a trial in the water. I find it very hard to swim in a straight line in the water and my right side of the fin seems to be slip on my foot and hence my fins tilt sideways. My first thought is that the fins are too big, but with my neoprene socks on, the foot pockets are snug and my front of my feet cramp after 15 mins. Anyone had these problems when first starting out w monofins or are they normal teething problems because of improper technique or something?