I have a series of elevation points from transect surveys completed on a river. I would like to interpolate this data to reveal the bathymetry of the river. The survey points are shown below:
I have tried the default options on topo to raster (cell size 109) and then used extract by mask to focus just on the river channel. It formed this raster below. The transect locations stand out clearly however I am hoping for a more continual surface. [![topo to raster output[2]](../../images/e694d05f28b1e1bae63aff42e88b6a15.webp)
I then tried IDW with a barrier polyline and this reduced the cell size down to 3. However there appears to be "seams" at the mid points between the transects. 
Can anyone recommend a method to interpolate these points into a smoother surface?