Weather forecasters have warned of flooding over the weekend.
High spring tides and large surge values mean there will be inner harbour flooding in some of the islands harbours between 11pm and 3am on Saturday/Sunday.
The areas most at risk in Douglas are the Tongue and the North Quay, but also parts of Lake Road and Tesco car park to a lesser extent.
For Ramsey, the areas most at risk are Mezeron Corner and West Quay, but the water may also reach into parts of Christian Street and Parliament Street. Flood defences need to be deployed for all low lying coastal areas.
With a fresh to strong southwest wind there is also a risk of some large waves leading to significant overtopping of sea water and debris onto exposed coastal roads and promenades around the time of high tide on Saturday and Sunday.
The areas most at risk are Shore Road Rushen (often called Gansey), Castletown Promenade, the northern end of Douglas Promenade, and Laxey and Ramsey promenades.