I want to have some  intellisense by casting my Model to DynamicNode, but once I do that I get errors. This works:

<nav> 
    <ul> 
        @foreach (var item in Model.AncestorOrSelf(1).Children.Where("umbracoNaviHide == false"))
        {  
            <li>
                <a href="@item.Url" @(item.Id == Model.Id ? "class=current" : "")>
                    @item.Name
                </a>
            </li> 
        }
    </ul> 
</nav> 

@using umbraco.MacroEngines;
@{ var currentPage = (DynamicNode)Model; }
<nav> 
    <ul> 
        @foreach (var item in currentPage.AncestorOrSelf(1).Children.Where("umbracoNaviHide == false"))
        {  
            <li>
                <a href="@item.Url" @(item.Id == Model.Id ? "class=current" : "")>
                    @item.Name
                </a>
            </li> 
        }
    </ul> 
</nav> 

I get an error:

'umbraco.MacroEngines.DynamicNode' does not contain a definition for 'Children' and no extension method 'Children' accepting a first argument of type 'umbraco.MacroEngines.DynamicNode'