That the crew can raise her to the surface at pleasure hoist sail and proceed on their [Voage] Voyage; as before descending;
Seventh
That where the water is not more than Sixty fathoms deep, and the current not more than four miles an hour, she can cast anchor and continue under water at any depth from one to fifty feet; that she will there remain as stationary as Vessels usually are while anchored on the surface;
Eighth
That in open Sea where bottom is not saught, she can plunge with safety and continue Under water while the air is respirable; but in this case she must drift with the tide like a vessel which cannot anchor and has no wind,
Ninth
That in Still water and while under water, she can move forwards, or backwards, to the right or left, mount or descend at pleasure;
Tenth
That She is capable of carrying 30 Submarine bombs each containing 100 pounds of powder
The preciding properties are all which are necessary, to a plunging Vessel, such a vessel cannot be taken in consequence of the ease with which she can hide under water during the day, she can make her approaches [in the night] in the night and must be considered as a masked [battery] Magazine which can lie secure in the neighbourhood of an Enemy watch an opportunity to deposit her cargo of Bombs and retire unperceived.