Statement-I is not correct because the temperature contrast between continents and oceans is in fact greater during winter than in summer. This is due to disparity in heat retention between land and water - continental landmasses cool much faster than oceans during the winter months, causing a larger contrast.

Statement-II is correct. Water has a higher specific heat which means it can absorb more heat before its temperature increases. On the other hand, land heats up and cools down more quickly than water. This difference in specific heat is why coastal areas usually have milder, more stable climates compared to inland regions.

Therefore, the correct answer is option 4: Statement-I is incorrect but Statement-II is correct.