Possible Clues:

• Projectile from lake is found in sea
• Projectile, large, is located in sea
• Of projectile motion
• British record in the greatest college is likely to rocket skywards
• Of projectiles
• Pellet and one short baton as some missiles
• Dance is for jerk moving under force of gravity
• Student is included in sea projectile
• Type of missile launched originally is found in sea
• Seems the missile is jerky enough to be a missile