Next week I'll have to go under and scrape it clean. Such abrasive protrusions as this seriously affect the planning of the trawler. This trawler is semi-displacement and requires smooth surfaces.
A full displacement hull will move the water away from its bow as its making way. (Abrasive protrusions such as barnacles, may not as greatly affect it. Though it would be affected.)
A planning hull will ride over the water as it makes way. (Barnacles and such protrusions are a detriment)
A semi displacement is somthing in between. And must be kept clear of abrasive protrusions for this reason.