Sull'inerenza dell'exercitio navis del servus al peculium

The sources testify that the exercitio navis could be carried out not only by a sui iuris, but also from an alieno iuri subiectus, tipically a slave. It's debated, however, whether this maritime activity of the servus (especially in the presence of voluntas of the dominus - that would lead to his responsibility in solidum -) realized itself within the peculium or within the part of the assets of the dominus. From the very definition of exercitor provided by Gaius and Ulpian, as well as through the analysis of certain passages which deal specifically with the exercitio navis - in particular, D. 14.1.1.20 (28 to Ulp. ad ed.) and D. 14.1.6 pr. (6 Paul. brev.) - descends that the exercitor made such activities, even in the presence of voluntas the dominus, in his own interest. It was also unnecessary that the ship was part of the peculium, but the servus needed to had it in his full availability.