Using Proj4Leaflet with a GeoJSON layer and a projection definition

1.0.0b2 version

HTML

<script src="//cdn.leafletjs.com/leaflet/v1.0.0-beta.2/leaflet.js"></script>
<link rel="stylesheet" href="//cdn.leafletjs.com/leaflet/v1.0.0-beta.2/leaflet.css">
<script src="//rawgit.com/kartena/Proj4Leaflet/leaflet-proj-refactor/lib/proj4-compressed.js"></script>
<script src="//rawgit.com/kartena/Proj4Leaflet/leaflet-proj-refactor/src/proj4leaflet.js"></script>
<script src="//scs14004.geog2510.uconn.edu/seabeds.json"></script>
<div id="map" class="map"></div>

CSS

html,
body {
  height: 100%;
  width: 100%;
  padding: 0;
  margin: 0;
  border: 0;
}

.map {
  height: 100%;
  width: 100%;
}

JavaScript

var map = L.map('map', {
  center: [41, -73],
  zoom: 9
});

var lDarkMatter = L.tileLayer('https://cartodb-basemaps-{s}.global.ssl.fastly.net/dark_nolabels/{z}/{x}/{y}.png');
map.addLayer(lDarkMatter);

function style(feature) {
  return {
    weight: 2,
    opacity: 1,
    color: 'white',
    dashArray: '3',
    fillOpacity: 0.7
  };
}

proj4.defs("EPSG:102656", "+proj=lcc +lat_1=41.2 +lat_2=41.86666666666667 +lat_0=40.83333333333334 +lon_0=-72.75 +x_0=304800.6096 +y_0=152400.3048 +ellps=GRS80 +datum=NAD83 +to_meter=0.3048006096012192 +no_defs");

var crs = {
  "type": "name",
  "properties": {
    "name": "urn:ogc:def:crs:EPSG::102656"
  }
};

seabeds.crs = crs;

var seabeds_layer = L.Proj.geoJson(seabeds, {
  style: style
}).addTo(map);

map.fitBounds(seabeds_layer.getBounds());