However , these were relatively ponderous , required both submarines to be stationary on the surface , took a long time to transfer stores .
However , these needed to be in radio contact with the replenished boat , all conspiring to make them rather easy targets .
However , these were relatively ponderous , required both submarines to be stationary on the surface , took a long time to transfer stores , and needed to be in radio contact with the replenished boat , all conspiring to make them rather easy targets .