The forward roll is most spectacular ... providing you get it right. Otherwise you just look stoopid.
The secret is not trying too hard and letting gravity work.
The hardest thing I've had to do is the ditch & don (just like James Bond). Wearing full gear, pootle to the 4m point of the pool, remove all gear and make safe (including switching off the cylinder), then return to the surface. Then return to the kit and put it all back on again. Sounds simple, but you use most of your breath just swimming (no diving down) down to the kit. Then its get the bloody regulator in the mouth, breathe in some water, curse, then switch on the cylinder, breathing in some more water then air. After that its relatively simple - providing you put your weight belt over your knee as you are kneeling on the bottom. The alternative is hilarious.
p.s. I did this for my Master Scuba Diver qual (under NAUI regs) and not through BSAC.
Another fun thing before this is to hold the BCD, cylinder (and loads of hoses) and mask, then jump in. Get down to the 4m point, then switch on the air and breathe, then don all the gear correctly.
Fun times.