Your old fashioned trainers are still fine for boating as long as they have a nonslip tread.
Try high-top basketball shoes for canoeing; they'll provide extra ankle support when you need it.
Aerobic shoes are suitable for playing tennis in (they give support for quick side-to-side movements), but don't do aerobics in tennis or running shoes - they lack sufficient cushioning under the ball of the foot.
Fit
Be sure your shoes have enough room for your toes to spread under your full weight; allow ½in/13mm between the end of your big toe and the tip of the shoe when you are standing on both feet.
Shoes should be snug and supportive in the heel, but not tight. If you have narrow heels, buy shoes with extra lacing holes towards the ankle or with high tops.
